Nihon Parkerizing Co., Ltd.

Nippon Steel & Sumikin Coated Sheet Corporation

Tomohiro Iko

Shigeki Yamamoto

Amane Suzuki

Hiromasa Nomura

Hidehiro Yamaguchi

Hiroyuki Oyokawa

Hidekazu Fukushi

Eisuke Kudo

Wei Li

Yohei Otsu

Masaru Tokue

The present invention addresses the problem of providing, a metal surface treatment agent capable of exhibiting excellent corrosion resistance and excellent coating adhesion in painted metal materials; and a metal surface treatment method using the metal surface treatment agent. The problem is solved by a pretreatment agent that is used in a pretreatment of a chemical conversion treatment performed for forming a chemical conversion coating on/over a surface of a metal material, the pretreatment agent containing: a metal alkoxide (A) containing at least one metal element selected from zirconium, titanium, vanadium, and aluminum; and at least one sulfonic acid (B) selected from methanesulfonic acid, ethanesulfonic acid, hydroxymethanesulfonic acid, and hydroxyethanesulfonic acid. The problem is also solved by a chemical conversion treatment agent that contains a zirconium alkoxide (a) and a zirconium-containing ion supply source (b), and has a pH of 1.5 to 6.5.

Pretreatment agent and chemical conversion treatment agent

The present invention addresses a problem of providing, for example, a metal surface treatment agent capable of forming a coating film that exhibits good corrosion resistance at edges, such as cut portions, of a coated metal material. The problem is solved by a metal surface treatment agent comprising: an ion (A) containing at least one kind of metal selected from zirconium, titanium and hafnium at a metal-equivalent molar concentration of 0.1 mmol/L or higher; and an aqueous urethane resin (B) having a weight-average molecular weight of 50,000 or higher at a solid mass concentration of 0.5 to 10 g/L, in which the ratio of a solid mass (B) of the resin (B) to a metal-equivalent mass (A) of the ion (A), [B/A], is 0.7 or higher.

Metal surface treatment agent, metal surface treatment method, and metal material

An aqueous surface treatment composition for coated steel sheet securing sufficient working adhesion while causing the formation of a surface treatment layer imparting excellent overhang corrosion resistance even without containing chrome, that is, a surface treatment composition containing a specific organic silicon compound, hexafluorometallic acid, a urethane resin having specific cationic groups, a vanadium compound, and an aqueous medium and sufficiently securing working adhesion while imparting excellent overhang corrosion resistance by the urethane resin having cationic groups and a total amine value of specific values is provided.

Surface treatment composition for coated steel sheet, surface treated plated steel sheet and method of production of same, and coated plated steel sheet and method of production of same

A composition for adhesion layer that is used for obtaining a multi-layered surface treatment steel sheet in which an adhesion layer is formed onto at least one surface of the steel sheet, and an upper layer and/or an intermediate layer which has a design and which contains a rust preventive pigment and/or a colored pigment is formed onto the adhesion layer; the composition including a cationic urethane resin and a silicon compound in an aqueous medium, and the ratio between the temperature at which the logarithmic decrement for the mixture of the cationic urethane resin and the silicon compound in the rigid-body pendulum type free damped vibration method shows the maximum value and the temperature at which the logarithmic decrement for the cationic urethane resin alone in the rigid-body pendulum type free damped vibration method shows the maximum value is in the range of 1.2 to 3.0.

Composition for adhesion layer used for multi-layered surface-treatment steel sheet

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Tokyo, Japan

Tomohiro Iko