Jfe Steel Corporation

Kansai Paint Company, Ltd.

Kazuhisa Okai

Akira Matsuzaki

Takeshi Matsuda

Takashi Nakano

Kenichi Sasaki

Hiroshi Kajiyama

Tatsuya Miyoshi

Naoto Yoshimi

Etsuo Hamada

Masahiro Murata

Takao Ooshima

Syoichi Tanaka

Reona Endo

Masahiro Yoshida

Takashi Kawano

Masaaki Yamashita

Daisuke Mizuno

Satoru Ando

Yusuke Fushiwaki

Yuichi Fukushima

Takafumi Yamaji

Keiji Yoshida

Toshiyuki Okuma

Rie Kaneko

Rie Umebayashi

Syuji Nomura

Reiko Yamaji, Legal Representative

Hiroki Harada

Fuyuko Ikeda

Disclosed is a method of producing a surface-treated steel sheet for organic resin coating comprising: applying, to a surface of a zinc or zinc alloy coated or plated steel sheet, a surface-treatment solution containing a resin compound having a specific bisphenol skeleton, a cationic urethane resin emulsion, a silane coupling agent having a specific reactive functional group, an organic titanium chelate compound, a tetravalent vanadium compound, a molybdate compound, a fluorine compound, and water in a specific ratio and with a pH of 4 to 5 to form a surface-treatment layer such that a coating weight of the surface-treatment layer per surface after drying of the surface-treatment solution is 0.005 g/mto 1.8 g/m.

Surface-treated steel sheet for organic resin coating and method of producing same, and organic resin coated steel sheet and method of producing same

A surface-treated steel sheet includes a chemical conversion coating with a thickness of 3.0 &#x3bc;m or less, the chemical conversion coating being placed on a surface of a hot-dip Zn&#x2014;Al alloy coated steel sheet including a hot-dip Zn&#x2014;Al alloy coating film containing Al: more than 1.0 mass % and 15 mass % or less, a balance being Zn and inevitable impurities. The chemical conversion coating contains AlHPO.2HO and a compound containing one or more elements selected from Mg, Ca, and Sr such that a sum of contents of AlHPO.2HO and the compound is 3.0 mass % to 50 mass %.

Surface-treated steel sheet

A steel sheet has a hot-dip Zn&#x2014;Al&#x2014;Mg-based coating film, the coating film containing 1 mass % to 22 mass % of Al and 0.1 mass % to 10 mass % of Mg on a surface of the steel sheet, in which an X-ray diffraction peak intensity ratio of a Mg&#x2014;Zn compound phase in the coating film, that is, MgZn/MgZn, is 0.2 or less.

Steel sheet having a hot-dip Zn&#x2014;Al&#x2014;Mg-based coating film excellent in terms of surface appearance and method of manufacturing the same

Disclosed is a surface-treatment solution for producing a zinc or zinc alloy coated steel sheet with a surface-coating layer that does not contain a chromium compound in the surface-coating layer and that is excellent in all of heat discoloration resistance, heat cracking resistance, planar part anti-corrosion property, corrosion resistance after alkali degreasing, blackening resistance, stack blackening resistance, anti-water stain property, solvent resistance, perspiration resistance, coating adhesion property, and storage stability. The disclosed surface-treatment solution contains a glycidyl group-containing silane coupling agent (A), a tetraalkoxysilane (B), a zirconium carbonate compound (C), and an anionic polyurethane resin (D) having a glass transition temperature (Tg) of 80&#xb0; C. to 130&#xb0; C., a vanadium compound (E), a molybdic acid compound (F), and water, the surface-treatment solution having a pH of 8.0 to 10.0, and the amount of each component satisfying a predetermined relationship.

Surface-treatment solution for zinc or zinc alloy coated steel sheet, method of producing zinc or zinc alloy coated steel sheet with surface-coating layer, and zinc or zinc alloy coated steel sheet with surface-coating layer

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/m. 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.

Surface-treated galvanized steel sheet with superior flat-portion corrosion resistance, blackening resistance, and appearance and corrosion resistance after press forming and aqueous surface-treatment liquid for galvanized steel sheet

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.

Surface-treated steel sheet with excellent corrosion resistance and method for manufacturing same

A surface-treated galvanized steel sheet includes a steel sheet, a zinc coating disposed on the steel sheet, and a film disposed on the zinc coating. The film has a thickness in the range of 0.01 to 3 &#x3bc;m and contains certain amounts of resin compound having a particular chemical structure, cationic urethane resin, vanadium compound, zirconium compound, compound having a phosphate group, and acid compound. The surface-treated galvanized steel sheet contains no hexavalent chromium in the film and is excellent in terms of corrosion resistance, alkali resistance, and solvent resistance.

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.

Surface-treated steel sheet and method for manufacturing the same

Highly corrosion-resistant surface-treated steel sheet and method for producing same

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 (&#x3b1;) 1 to 2000 mg/mof silica in terms of SiO, (&#x3b2;) a total of 1 to 1000 mg/mof phosphoric acid groups in terms of P, (&#x3b3;) a total of 0.5 to 800 mg/mof at least one metal selected from Mg, Mn, and Al, and (&#x3b4;) 0.1 to 50 mg/mof a tetravalent vanadium compound; and a second layer film formed to a thickness of 0.1 to 5 &#x3bc;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.

Surface-treated steel sheet excellent in corrosion resistance, conductivity, and coating appearance

Growing community of inventors

Hiroshima, Japan

Kazuhisa Okai