Abstract: A zinc or zinc alloy coated steel excellent in various properties including corrosion resistance and adhesion properties and, in particular, good conductivity is provided. A method for manufacturing a zinc or zinc alloy coated steel sheet includes: preparing a surface-treatment liquid for a the steel sheet, containing following components, by blending the including: (A) a specific resin emulsion; (B) a tetraalkoxysilane; (C) at least one type of silane coupling agent; (D) a chelating agent; (E) a vanadate compound; (F) a titanium compound; and water; and applying by coating the surface-treatment liquid to a surface of the steel sheet, heating and drying the surface of the steel sheet such that a coating amount per one surface is 200 to 1,000 mg/m2 to form a surface treatment coating film on the surface.

Abstract: An aqueous surface-treatment liquid is a treatment liquid containing a water-soluble zirconium compound, water-dispersive particulate silica, a silane coupling agent, a vanadic acid compound, a phosphoric acid compound, a nickel compound, and an acrylic resin emulsion in particular proportions. A surface-treated galvanized steel sheet produced using the treatment liquid is a galvanized steel sheet having a surface-treatment coating on a surface thereof, and the coating contains a zirconium compound, particulate silica, a silane-coupling-agent-derived component, a vanadic acid compound, a phosphoric acid compound, a nickel compound, and an acrylic resin in particular proportions. The amount of coating on a zirconium basis is 10 to 200 mg/m2. This surface-treated galvanized steel sheet is chromate-free and has superior flat-portion corrosion resistance, blackening resistance, and appearance and corrosion resistance after press forming.

Abstract: There is provided a galvanized steel sheet that has various properties such as corrosion resistance and adhesion and allows for high conductivity at a low contact pressure. A first layer film is formed by applying a surface treatment solution having a pH of 8 to 10 onto the surface of the galvanized steel sheet and drying the surface treatment solution by heating, the surface treatment solution containing a water-soluble zirconium compound, a tetraalkoxysilane, an epoxy group-containing compound, a chelating agent, a silane coupling agent, vanadic acid, and a metal compound in a specific ratio. Subsequently, a second layer film is formed by applying a surface treatment solution containing an organic resin onto the surface of the first layer film and drying the surface treatment solution by heating.

Abstract: A galvanized steel sheet includes a surface-treatment film with 50 to 1200 mg/m2, wherein the surface-treatment film is obtained by applying a surface-treatment agent to a surface of a galvanized steel sheet and drying the surface-treatment agent by heating; and the surface-treatment agent is prepared as a mixture having a pH of 8 to 10 and containing, with specific proportions, a water-soluble zirconium compound, a tetraalkoxysilane, an epoxy-group-containing compound, a chelating agent, a silane coupling agent, vanadic acid, and a metal compound.

Abstract: A method for making a phosphate-treated galvanized steel sheet, including forming a phosphate film on the surface of a galvanized layer of a galvanized steel sheet using a phosphate treatment solution containing Zn2+ and Mg2+ so as to satisfy 2.0<Zn2+?5.0 g/L, 2.0?Mg2+?5.0 g/L, and 0.4?Mg2+/Zn2+?2.5, and satisfying 0.020?free acidity/total acidity<0.10. The method allows for the quick formation of a uniform phosphate film, whereby a phosphate-treated galvanized steel sheet having excellent corrosion resistance and blackening resistance is obtained.

Abstract: The surface-treated steel sheet has a zinc-based plated steel sheet, a surface-treatment coating being formed on the surface of the zinc-based steel sheet by applying and drying a surface treatment coating composition thereon, and a top coating being formed by applying and drying a coating composition for top coating on the surface-treatment coating. The surface treatment coating composition contains a water-epoxy resin dispersion, a silane coupling agent, and phosphoric acid and/or a hexafluorometal acid. The coating composition for top coating contains a high molecular weight epoxy group-containing resin having number average molecular weights ranging from 6000 to 20000.

Abstract: An object of the present invention is to keep an appropriate high pressure side pressure in a refrigerant circuit while reducing noises of an operation of a blower in a refrigerating apparatus which obtains a critical pressure on a high pressure side. The refrigerating apparatus in which the refrigerant circuit is constituted of a compressor, a gas cooler, reducing means and an evaporator to obtain a supercritical pressure on the high pressure side comprises a blower which air-cools the gas cooler and a control device which controls this blower. This control device controls a revolution speed of the blower based on an outdoor temperature and an evaporation temperature of a refrigerant in the evaporator.

Abstract: The present invention provides a surface treated steel sheet including a steel sheet; a plating layer containing at least one metal selected from the group consisting of zinc and aluminum on a surface of the steel sheet; and a film on the plating layer, the film containing at least one metal selected from the group consisting of Al, Mg, and Zn, a tetravalent vanadium compound, and a phosphoric acid group. This surface treated steel sheet exhibits excellent corrosion resistance and excellent surface appearance without containing hazardous substances, such as hexavalent chromium, in the film.

Abstract: An aqueous surface-treatment liquid is a treatment liquid containing a water-soluble zirconium compound, water-dispersive particulate silica, a silane coupling agent, a vanadic acid compound, a phosphoric acid compound, a nickel compound, and an acrylic resin emulsion in particular proportions. A surface-treated galvanized steel sheet produced using the treatment liquid is a galvanized steel sheet having a surface-treatment coating on a surface thereof, and the coating contains a zirconium compound, particulate silica, a silane-coupling-agent-derived component, a vanadic acid compound, a phosphoric acid compound, a nickel compound, and an acrylic resin in particular proportions. The amount of coating on a zirconium basis is 10 to 200 mg/m2. This surface-treated galvanized steel sheet is chromate-free and has superior flat-portion corrosion resistance, blackening resistance, and appearance and corrosion resistance after press forming.

Abstract: A surface-treated steel sheet is disclosed, including a zinc based plated steel sheet having thereon a surface-treated film containing titanium, nickel, aluminum and fluorine and having a film thickness of from 0.05 to 1.0 ?m, the surface-treated film having a titanium deposition amount of from 0.01 to 0.5 g/m2 and containing from 0.01 to 5 parts by mass of nickel, from 0.1 to 25 parts by mass of aluminum and from 1 to 500 parts by mass of fluorine relative to 100 parts by mass of titanium. This surface-treated steel sheet does not contain hexavalent chromium in the film thereof at all and has excellent heat discoloration resistance, corrosion resistance and resistance to blackening.

Abstract: The surface-treated steel sheet has a zinc-based plated steel sheet, a surface-treatment coating being formed on the surface of the zinc-based steel sheet by applying and drying a surface treatment coating composition thereon, and a top coating being formed by applying and drying a coating composition for top coating on the surface-treatment coating. The surface treatment coating composition contains a water-epoxy resin dispersion, a silane coupling agent, and phosphoric acid and/or a hexafluorometal acid. The coating composition for top coating contains a high molecular weight epoxy group-containing resin having number average molecular weights ranging from 6000 to 20000.

Abstract: A surface-treated steel sheet includes a steel sheet; a plating layer containing at least one metal selected from zinc and aluminum; a first layer film containing (?) 1 to 2000 mg/m2 of silica in terms of SiO2, (?) a total of 1 to 1000 mg/m2 of phosphoric acid groups in terms of P, (?) a total of 0.5 to 800 mg/m2 of at least one metal selected from Mg, Mn, and Al, and (?) 0.1 to 50 mg/m2 of a tetravalent vanadium compound; and a second layer film formed to a thickness of 0.1 to 5 ?m on the first layer film and containing a resin (A) having at least one type of functional group selected from OH and COOH groups, and at least one rust-proofing additive (B) selected from (a) a phosphate, (b) Ca ion-exchanged silica, (c) a molybdate, (d) silicon oxide, and (e) at least one organic compound selected from triazoles, thiols, thiadiazoles, thiazoles, and thiurams.

Abstract: A surface-treated steel sheet has a zinc-based or an aluminum-based plated steel sheet, a surface-treatment coating being formed on the surface of the zinc-based or aluminum-based steel sheet by applying and drying a surface treatment coating composition thereon, and a top coating being formed by applying and drying a coating composition for top coating on the surface-treatment coating. The surface treatment coating composition contains a water-epoxy resin dispersion, a water dispersed polyurethane resin, a silane coupling agent, and phosphoric acid and/or a hexafluorometal acid. The coating composition for a top coating contains a high molecular weight epoxy group-containing resin average molecular weight of 6,000 to 20,000.

Abstract: A surface-treated steel sheet is disclosed, including a zinc based plated steel sheet having thereon a surface-treated film containing titanium, nickel, aluminum and fluorine and having a film thickness of from 0.05 to 1.0 ?m, the surface-treated film having a titanium deposition amount of from 0.01 to 0.5 g/m2 and containing from 0.01 to 5 parts by mass of nickel, from 0.1 to 25 parts by mass of aluminum and from 1 to 500 parts by mass of fluorine relative to 100 parts by mass of titanium. This surface-treated steel sheet does not contain hexavalent chromium in the film thereof at all and has excellent heat discoloration resistance, corrosion resistance and resistance to blackening.

Abstract: The invention is to provide a surface-treated steel sheet of good white rust resistance with no chromium in its surface treatment film, and it has realized a surface-treated steel sheet of higher-level corrosion resistance by forming a reaction layer of plating metal with a barrier layer effective for anticorrosion not in a two-layered film but in a single-layered film.

Abstract: The present invention provides a surface treated steel sheet including a steel sheet; a plating layer containing at least one metal selected from the group consisting of zinc and aluminum on a surface of the steel sheet; and a film on the plating layer, the film containing at least one metal selected from the group consisting of Al, Mg, and Zn, a tetravalent vanadium compound, and a phosphoric acid group. This surface treated steel sheet exhibits excellent corrosion resistance and excellent surface appearance without containing hazardous substances, such as hexavalent chromium, in the film.

Abstract: The present invention provides a surface-treated steel sheet including a steel sheet; a plating layer provided on at least one of the surfaces of the steel sheet, the plating layer containing at least one metal selected from the group consisting of zinc and aluminum; a first layer film provided on the surface of the plating layer and containing (?) 1 to 2000 mg/m2 of silica in terms of SiO2, (?) a total of 1 to 1000 mg/m2 of phosphoric acid groups in terms of P, (?) a total of 0.5 to 800 mg/m2 of at least one metal selected from the group consisting of Mg, Mn, and Al in terms of a metal element, and (?) 0.1 to 50 mg/m2 of a tetravalent vanadium compound in terms of V; and a second layer film formed to a thickness of 0.

Abstract: The surface-treated steel sheet has a zinc-based plated steel sheet, a surface-treatment coating being formed on the surface of the zinc-based steel sheet by applying and drying a surface treatment coating composition thereon, and a top coating being formed by applying and drying a coating composition for top coating on the surface-treatment coating. The surface treatment coating composition contains a water-epoxy resin dispersion, a silane coupling agent, and phosphoric acid and/or a hexafluorometal acid. The coating composition for top coating contains a high molecular weight epoxy group-containing resin having number average molecular weights ranging from 6000 to 20000.

Abstract: The invention is to provide a surface-treated steel sheet of good white rust resistance with no chromium in its surface treatment film, and it has realized a surface-treated steel sheet of higher-level corrosion resistance by forming a reaction layer of plating metal with a barrier layer effective for anticorrosion not in a two-layered film but in a single-layered film.

Abstract: A surface-treated steel sheet includes a steel sheet, an Al—Zn-base alloy plating layer formed on the steel sheet, a chemical conversion film provided on the alloy plating layer, and a concentric layer of a Cr compound that is formed on the alloy plating layer of the chemical conversion film. The surface-treated steel sheet may include a steel sheet, an zinc-base plating layer formed on the steel sheet, and a film that contains chromium and calcium and that is formed on the zinc-base plating layer.