A method of manufacturing hydrophilic stainless steel includes polishing the surface of the stainless steel in one direction; and immersing the polished stainless steel in an acidic solution to form an oxide film.

A method of manufacturing hydrophilic stainless steel includes polishing the surface of the stainless steel in one direction; and immersing the polished stainless steel in an acidic solution to form an oxide film.

A surface treatment agent capable of forming a hexavalent chromium-free chemical conversion coating that can provide an excellent corrosion-resistant coating on various metallic materials; a metallic material having a surface treatment coating obtained therefrom; and a method of producing the same. A free fluorine ion-containing surface treatment agent for surface-treating a metallic material, which is obtained by mixing at least one supply source (A) of trivalent chromium-containing ions A; a supply source (B) of ions B that are at least one selected from titanium-containing ions and zirconium-containing ions; a water-soluble or water-dispersible compound (C) containing an alkoxysilyl group, an aromatic ring, a hydroxy group directly bonded to the aromatic ring, and at least one of primary, secondary, tertiary and quaternary amino groups, wherein the alkoxysilyl group is bonded to the nitrogen atom of the amino group directly or via an alkylene group; and a fluorine-containing compound (D) providing fluorine-containing ions.

A surface treatment agent capable of forming a hexavalent chromium-free chemical conversion coating that can provide an excellent corrosion-resistant coating on various metallic materials; a metallic material having a surface treatment coating obtained therefrom; and a method of producing the same. A free fluorine ion-containing surface treatment agent for surface-treating a metallic material, which is obtained by mixing at least one supply source (A) of trivalent chromium-containing ions A; a supply source (B) of ions B that are at least one selected from titanium-containing ions and zirconium-containing ions; a water-soluble or water-dispersible compound (C) containing an alkoxysilyl group, an aromatic ring, a hydroxy group directly bonded to the aromatic ring, and at least one of primary, secondary, tertiary and quaternary amino groups, wherein the alkoxysilyl group is bonded to the nitrogen atom of the amino group directly or via an alkylene group; and a fluorine-containing compound (D) providing fluorine-containing ions.

This disclosure relates to use of a conversion coating for reduction or prevention of hydrogen sulfide production in cans holding hydrogen sulfide producing liquids, such as wine. This disclosure also relates to metal cans comprising a conversion coating layer deposited on at least a portion of the inside surface of the metal can, a film-forming layer deposited on such conversion coating layer, and a hydrogen sulfide producing liquid deposited inside the metal can.

This disclosure relates to use of a conversion coating for reduction or prevention of hydrogen sulfide production in cans holding hydrogen sulfide producing liquids, such as wine. This disclosure also relates to metal cans comprising a conversion coating layer deposited on at least a portion of the inside surface of the metal can, a film-forming layer deposited on such conversion coating layer, and a hydrogen sulfide producing liquid deposited inside the metal can.

A reactive chemical conversion treatment liquid capable of forming a Si-containing chemical conversion film is provided. The chemical conversion treatment liquid contains colloidal silica, a trivalent chromium-containing water-soluble substance, and a high pKa organic acid-containing water-soluble substance such as a hydroxymonocarboxylic acid and may further contain a film-formable metal-containing water-soluble substance in a preferred embodiment, and the pH of the chemical conversion treatment liquid is 3.0 or more.

A reactive chemical conversion treatment liquid capable of forming a Si-containing chemical conversion film is provided. The chemical conversion treatment liquid contains colloidal silica, a trivalent chromium-containing water-soluble substance, and a high pKa organic acid-containing water-soluble substance such as a hydroxymonocarboxylic acid and may further contain a film-formable metal-containing water-soluble substance in a preferred embodiment, and the pH of the chemical conversion treatment liquid is 3.0 or more.

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. The composition is free from allylamine, polyallylamine, aromatic sulphonic acid, aromatic sulphonic acid-formaldehyde condensate, and derivatives thereof, and fluorine-based substance, hexavalent chromium-containing substance, and film-forming organic component.

Aqueous compositions useful as pretreatments prior to painting and to prevent the formation of white rust in the uncoated condition include an organopolyphosphonic acid or salt thereof, an organosilane, and a trivalent chromium compound. A method for treating a surface of a zinc-containing metal includes contacting the surface with an aqueous composition including an organopolyphosphonic acid or salt thereof, an organosilane, and a trivalent chromium compound. The composition may also include an agent for reducing hydrophilicity, such as a polyacrylic acid. The aqueous composition has been found to be particularly well-suited for treating a zinc-containing metal to passivate the surface, improve paint adhesion, and/or improve corrosion resistance.