Abstract: The present invention provides an inorganic-organic composite-treated zinc-plated steel sheet whose treated coatings do not contain any chromium and which is excellent in corrosion resistance after degreasing, coating adhesion and electrodeposition coating performance. The inorganic-organic composite-treated zinc-plated steel sheet, which is obtained by forming a zinc phosphate coating, in a coating weight of 0.3 to 5 g/m2, on the zinc-plated steel sheet surface and forming thereon a post-treatment coating, in a coating weight of 0.01 to 1 g/m2, by using a post-treatment composition containing at least one compound (A) selected from the group consisting of thiocarbonyl group-containing compounds, sulfide group-containing compounds and guanidyl group-containing compounds, an organic resin (B), a crosslinking agent (C) and an inorganic corrosion inhibitor (D).

Abstract: The present invention is intended to provide an inorganic-organic composite-treated zinc-plated steel sheet whose treated coatings do not contain any hazardous chromate and which is excellent in corrosion resistance after alkaline degreasing and coating adhesion. An inorganic-organic composite-treated zinc-plated steel sheet which has a zinc phosphate coating, in a coating weight of 0.3 to 5 g/m2, on the zinc-plated steel sheet surface and, thereon, a post-treatment coating, in a coating weight of 0.01 to 1 g/m2, containing an organic resin (A), a zirconium compound (B), an inorganic corrosion inhibitor (C) and an organic corrosion inhibitor (D).

Abstract: The present invention is intended to provide an inorganic-organic composite-treated zinc-plated steel sheet whose treated coatings do not contain any hazardous chromate and which is excellent in corrosion resistance after alkaline degreasing and coating adhesion. An inorganic-organic composite-treated zinc-plated steel sheet which has a zinc phosphate coating, in a coating weight of 0.3 to 5 g/m2, on the zinc-plated steel sheet surface and, thereon, a post-treatment coating, in a coating weight of 0.01 to 1 g/m2, containing an organic resin (A), a zirconium compound (B), an inorganic corrosion inhibitor (C) and an organic corrosion inhibitor (D).

Abstract: It is an object of the present invention to provide a metal surface treatment composition and a metal surface treatment method superior in stability, which can apply a good chemical conversion treatment to a galvanized steel plate without requiring a burden of waste water treatment, and a galvanized steel plate superior in a rust-preventive property and adhesion, which is obtained by such a metal surface treatment method. A metal surface treatment composition comprising niobium oxide colloidal particles, wherein the niobium oxide colloidal particles are derived from a niobium oxide sol which is stabilized by containing citric acid or salts thereof in an amount of 0.02 to 1.0 by a mole ratio relative to Nb.

Abstract: The present invention provides an inorganic-organic composite-treated zinc-plated steel sheet whose treated coatings do not contain any chromium and which is excellent in corrosion resistance after degreasing, coating adhesion and electrodeposition coating performance. The inorganic-organic composite-treated zinc-plated steel sheet, which is obtained by forming a zinc phosphate coating, in a coating weight of 0.3 to 5 g/m2, on the zinc-plated steel sheet surface and forming thereon a post-treatment coating, in a coating weight of 0.01 to 1 g/m2, by using a post-treatment composition containing at least one compound (A) selected from the group consisting of thiocarbonyl group-containing compounds, sulfide group-containing compounds and guanidyl group-containing compounds, an organic resin (B), a crosslinking agent (C) and an inorganic corrosion inhibitor (D).

Abstract: A metal surface treatment composition is provided which improves corrosion resistance and film adhesion, and confers slip properties. This composition is an acrylic resin-containing metal surface treatment composition which is water-soluble, water-dispersible or emulsifiable, which comprises an acrylic resin, this resin comprising either or both of an amino group and an ammonium group together with a hydroxyl group and a hydrophobic group, and which further comprises a heavy metal or one of its salts.

Abstract: A metal surface treatment composition which can improve the corrosion resistance and the tight adhesion to coating films and impart slipperiness. The composition is an aqueous solution, dispersion or emulsion containing both an acrylic resin having nitrogenous heterocycles, amino and/or ammonium groups and hydrophobic groups and a heavy metal or a salt thereof. The amino or ammonium groups have at least one structure selected from among those represented by general formulae (I) (wherein in R.sub.1, R.sub.2 : hydrogen, hydroxyl, substituted or unsubstituted, linear or branched C.sub.1 -C.sub.5 alkyl, or substituted or unsubstituted, linear or branched C.sub.1 -C.sub.5 hydroxyalkyl) and (II) (wherein R.sub.3, R.sub.4, R.sub.5 : hydrogen, hydroxyl, substituted or unsubstituted, linear or branched C.sub.1 -C.sub.5 alkyl, or substituted or unsubstituted, linear or branched C.sub.1 -C.sub.5 hydroxyalkyl).

Abstract: A flux composition for brazing of an aluminum material which can feed a proper amount of flux to an area to be joined at the time of brazing and at the same time can improve working environment, and a method for brazing of an aluminum material. The method comprises: coating an aluminum material to be joined with a flux composition comprising 0.5 to 25 parts by weight of a polymeric compound having a number average molecular weight of 50000 to 5000000 and comprising repeating alkylene oxide units, 5 to 30 parts by weight of a fluoride flux, and water added in such an amount as will provide a total amount of the composition of 100 parts by weight; heating the coated area to remove water; heating the coated area to decompose and remove the polymeric compound; and then conducting heating for brazing.

Abstract: A surface-treated metal material wherein a film comprising an organic polymer compound having 5-100 mg of carbon per m.sup.2 and a phosphoric acid compound having 1-30 mg of phosphorus per m.sup.2 is formed on a metal surface, the ratio C/P of carbon atoms C to phosphorus atoms P in the film lying within the range 2-25.