Abstract: As a rust prevention member that has excellent corrosion resistance, while being provided with a coating film that contains Si, a rust prevention member which is provided with a base material, a zinc-based plating layer that is provided on the base material, and a chemical conversion coating film that contains Si and is provided on the zinc-based plating layer is described. This rust prevention member is characterized in that the chemical conversion coating film has an Si-rich region on the surface side, said Si-rich region having an atomic ratio of the Si content to the Zn content of 1 or more, while having a thickness of 100 nm or more.

Abstract: Provided is a metal-particle dispersion composition as a composition containing dispersed metal particles and being suitable for use in aqueous coating compositions, etc., the metal-particle dispersion composition comprising 10-80 mass % metal particles, 0.01-10 mass % organic titanate compound in a chelate form, 1-40 mass % water, and 2-30 mass % organic solvent having a higher boiling point than water, the amounts being based on the whole composition, wherein the organic titanate compound is an organic compound represented by Ti(OR)4 (the OR groups include at least one chelatable substituent based on triethanolamine) and the organic solvent having a higher boiling point than water is a C7 or lower alcohol compound.

Abstract: Provided is a metal-particle dispersion composition as a composition containing dispersed metal particles and being suitable for use in aqueous coating compositions, etc., the metal-particle dispersion composition comprising 10-80 mass % metal particles, 0.01-10 mass % organic titanate compound in a chelate form, 1-40 mass % water, and 2-30 mass % organic solvent having a higher boiling point than water, the amounts being based on the whole composition, wherein the organic titanate compound is an organic compound represented by Ti(OR)4 (the OR groups include at least one chelatable substituent based on triethanolamine) and the organic solvent having a higher boiling point than water is a C7 or lower alcohol compound.

Abstract: Provided is a method for suppressing an increase in the zinc concentration of a plating solution when a zinc alloy plating member using nickel as an alloy element is manufactured using a zinc alloy plating apparatus. The plating apparatus includes: a plating tank; a first diaphragm tank having a first diaphragm; a cathode holding member; a first anode holding member; a soluble zinc-containing member held by the first anode holding member; a soluble metal-containing member containing the nickel which is the alloy element; and a second anode holding member for anode-electrolyzing the soluble metal-containing member. The first diaphragm tank is arranged in a manner that the first electrolytic solution is in contact with one surface of the first diaphragm and the plating solution is in contact with the other surface of the first diaphragm during use.

Abstract: Provided is a metal-particle dispersion composition as a composition containing dispersed metal particles and being suitable for use in aqueous coating compositions, etc., the metal-particle dispersion composition comprising 10-80 mass % metal particles, 0.01-10 mass % organic titanate compound in a chelate form, 1-40 mass % water, and 2-30 mass % organic solvent having a higher boiling point than water, the amounts being based on the whole composition, wherein the organic titanate compound is an organic compound represented by Ti(OR)4 (the OR groups include at least one chelatable substituent based on triethanolamine) and the organic solvent having a higher boiling point than water is a C7 or lower alcohol compound.

Abstract: As a rust prevention member that has excellent corrosion resistance, while being provided with a coating film that contains Si, a rust prevention member which is provided with a base material, a zinc-based plating layer that is provided on the base material, and a chemical conversion coating film that contains Si and is provided on the zinc-based plating layer is described. This rust prevention member is characterized in that the chemical conversion coating film has an Si-rich region on the surface side, said Si-rich region having an atomic ratio of the Si content to the Zn content of 1 or more, while having a thickness of 100 nm or more.

Abstract: A production method of a member having a surface provided thereon with a chemical conversion coating includes a contacting step and a washing step. The contacting step causes a reactive-type chemical conversion treating acidic composition to contact with a base material having a metal-based surface thereby forming a chemical conversion coating on the metal-based surface of the base material. The washing step washes the base material having been subjected to the contacting step to obtain a member having a surface provided thereon with the chemical conversion coating. The reactive-type chemical conversion treating acidic composition contains a water-soluble trivalent chromium-containing substance, a water-soluble titanium-containing substance, and a carboxylic acid compound. The acidic composition is free from a water-soluble cobalt-containing substance.

Abstract: An aqueous acidic composition is provided for forming a chromium-containing chemical conversion coating on a member having an iron-based metal surface. The composition contains a water-soluble trivalent chromium-containing substance, a water-soluble zinc-containing substance, and a water-soluble polyvalent carboxylic acid compound. On the total composition basis, the water-soluble trivalent chromium-containing substance has a content of 60 mmol/L or more in terms of chromium, the water-soluble zinc-containing substance has a molar content in terms of zinc such that a ratio of the content is 0.6 or more to a molar content in terms of chromium of the water-soluble trivalent chromium-containing substance, and the water-soluble polyvalent carboxylic acid compound has a content of 55 mmol/L or more in terms of polyvalent carboxylic acid.

Abstract: An additive for an acid zinc alloy plating bath includes an aliphatic polyamine having not more than 12 carbon atoms. The acid zinc alloy plating bath includes a buffer including an acetic acid-containing material containing acetic acid and/or acetate ions. A method for producing a zinc alloy plated article including an article and a zinc alloy plated coating formed on a plating surface of the article includes forming the zinc alloy plated coating by electroplating using the acid zinc alloy plating bath.

Abstract: A finishing agent satisfies a condition that (A) the ratio of the chromium equivalent molar concentration of a water-soluble trivalent chromium-containing substance contained in the finishing agent relative to the phosphorus equivalent molar concentration of a water-soluble phosphoric acid-based compound contained in the finishing agent is 0.5 or more, or a condition that (B) a water-soluble aluminum-containing substance and/or a water-soluble zirconium-containing substance are contained in the finishing agent such that the ratio of the total of the chromium equivalent molar concentration of the water-soluble trivalent chromium-containing substance, the aluminum equivalent molar concentration of the water-soluble aluminum-containing substance, and the zirconium equivalent molar concentration of the water-soluble zirconium-containing substance relative to the phosphorus equivalent molar concentration of the water-soluble phosphoric acid-based compound is 0.5 or more.

Abstract: A rust-preventive coating comprises two layers of coatings contacted with each other, wherein among the two layers of coatings, a first coating as a coating at an inner layer side is obtained from a first paint composition that contains a first metal-based powder and a first binder component, among the two layers of coatings, a second coating as a coating at an outer layer side is obtained from a second paint composition that contains a second metal-based powder and a second binder component, and compositions are different between the first metal-based powder and the second metal-based powder.

Abstract: The present invention provide a composition for a chemical conversion treatment capable of forming a chemical conversion film having both an excellent black appearance such that the L-value of the film is 28 even when the film is formed from the composition which has been aged, and good corrosion resistance. The composition is a water-soluble composition and comprising a trivalent chromium-containing substance, a cobalt-containing substance, a sulfur compound, and an organic phosphonate compound consisting of one or more compounds selected from the group consisting of organic phosphonic acids, ions of organic phosphonic acids, and organic phosphonates, and a nickel-containing substance as needed. It is preferable that the content of the trivalent chromium-containing substance be 1 to 10 g/L in chromium content equivalent, that the content of the cobalt-containing substance be 0.1 to 10 g/L in cobalt content equivalent, that the content of the sulfur compound be 0.

Abstract: A plating apparatus includes a plating bath, an insoluble anode located in the plating bath, a plating electric power supply being capable of applying a voltage between the insoluble anode and the member to be plated, an anode-displacement mechanism being capable of moving the insoluble anode in the plating bath and of holding the insoluble anode at a predetermined position in the plating bath, and a controller having an anode-position controller being capable of generating a control signal for controlling an action of the anode-displacement mechanism and of outputting the control signal to the anode-displacement mechanism.

Abstract: The object of this present invention is to provide novel means for inhibiting elution of hexavalent chromium from a chemical conversion coating. A composition for chemical conversion treatment comprises at least 0.1 g/L of a polyphenol and at least 1.5 g/L in chromium ion equivalent of an aqueous trivalent chromium compound and has a pH of 6 or less. A chemical conversion coating formed on a metallic surface of a member by contacting the surface with the composition for chemical conversion treatment has a hexavalent chromium content of 0.04 ?g/cm2 or less after exposure to an environment having a temperature of 80 degrees C. and a relative humidity of 100% for 120 hours. The content of hexavalent chromium is measured by a method compliant with EN15205. A composition containing at least 0.1 g/L of a polyphenol can be used as a composition for post-coating treatment of a chemical conversion coating obtained by conventional chemical conversion treatment.

Abstract: A plating apparatus includes a plating bath, an insoluble anode located in the plating bath, a plating electric power supply being capable of applying a voltage between the insoluble anode and the member to be plated, an anode-displacement mechanism being capable of moving the insoluble anode in the plating bath and of holding the insoluble anode at a predetermined position in the plating bath, and a controller having an anode-position controller being capable of generating a control signal for controlling an action of the anode-displacement mechanism and of outputting the control signal to the anode-displacement mechanism.

Abstract: An aqueous acidic composition is provided for forming a chromium-containing chemical conversion coating on a member having an iron-based metal surface. The composition contains a water-soluble trivalent chromium-containing substance, a water-soluble zinc-containing substance, and a water-soluble polyvalent carboxylic acid compound. On the total composition basis, the water-soluble trivalent chromium-containing substance has a content of 60 mmol/L or more in terms of chromium, the water-soluble zinc-containing substance has a molar content in terms of zinc such that a ratio of the content is 0.6 or more to a molar content in terms of chromium of the water-soluble trivalent chromium-containing substance, and the water-soluble polyvalent carboxylic acid compound has a content of 55 mmol/L or more in terms of polyvalent carboxylic acid.

Abstract: An acidic aqueous composition for semiglossy tin electroplating has a water-soluble tin (II)-containing substance and a surfactant. The surfactant includes a surfactant (A) comprising N,N?,N?-polyoxyethylene-N-alkyl-1,3-diaminopropane. The surfactant (A) the number of carbon atoms of the alkyl group that bonds to N ranges from 14 to 18. The weight-average molecular weight of the surfactant (A) ranges from 300 to 1500.

Abstract: The following two means are provided for a finishing agent for a chemical conversion coating wherein the finishing agent is capable of forming a finishing coating having an excellent corrosion resistance and excellent appearance as well as being suppressed in the elution of trivalent chromium: (A) the ratio of the chromium equivalent molar concentration of a water-soluble trivalent chromium-containing substance contained in the finishing agent relative to the phosphorus equivalent molar concentration of a water-soluble phosphoric acid-based compound contained in the finishing agent is 0.

Abstract: A rust-preventive coating comprises a zinc-containing coating obtained by heating a liquid layer comprising a zinc-containing inorganic-based paint that contains: an inorganic binder including an organic silicon compound and an organic titanate compound; and a metal-based powder, wherein the metal-based powder comprises aluminum-based powder and zinc-based powder, and this aluminum-based powder is such that a particle size D50 when a percent passing by weight is 50% in a particle-size accumulation curve is 10 ?m or more and 20 ?m or less, a leafing value is 70% or more, and a mass ratio to the metal-based powder is 10 mass % or more and 40 mass % or less.

Abstract: A rust-preventive coating comprises two layers of coatings contacted with each other, wherein among the two layers of coatings, a first coating as a coating at an inner layer side is obtained from a first paint composition that contains a first metal-based powder and a first binder component, among the two layers of coatings, a second coating as a coating at an outer layer side is obtained from a second paint composition that contains a second metal-based powder and a second binder component, and compositions are different between the first metal-based powder and the second metal-based powder.