Abstract: A fast and brightly colored oxide film of aluminum which excels in durability and allows no separation of pigment is produced by using an aqueous dispersion of an organic pigment or carbon black finely divided to a size in the range between 3 and 150 nm, forming on a surface of an aluminum member an anodic oxide film containing pores larger in diameter than the ordinary pores, and causing the organic pigment or carbon black to migrate and deposit in the pores of the oxide film by means of electrophoresis. The formation of the anodic oxide film containing the pores larger in diameter than the ordinary pores is accomplished in the first method by subjecting the aluminum member to anodic oxidation at a high voltage in an aqueous solution of acid.

Abstract: Durable and clear blue color of freely controlled density can be expeditiously and efficiently impated to an anodic oxide film of aluminum by a method which comprises forming the anodic oxide film on the aluminum or aluminum alloy, then subjecting the aluminum or aluminum alloy to AC electrolysis in a bath containing an inorganic ferrous salt as a main component thereof thereby inducing deposition of iron in the pores of the oxide film, and subsequently placing the aluminum or aluminum alloy as an anode in a bath containing hexacyano iron (II) acid salt as a main component thereof and subjecting the same to DC electrolysis therein. In the alternative method, the pore-widening treatment is added next to said step of anodic oxidation. The pore-widening treatment is effected by immersing the aluminum or aluminum alloy in sulfuric acid or phosphoric acid or electrolyzing the same in phosphoric acid or a mixed solution of phosphoric acid and sulfuric acid.

Abstract: An aluminum or aluminum alloy material is subjected to anodic oxidation, then to a treatment of electrophoresis in a bath containing a hexacyanoferrate (II) or hexacyanoferrate (III), and subsequently to a treatment of immersion in a bath containing at least one metal salt selected from the group consisting of salts of Fe, Ni, Co, Cu, Zn, Cd, Ba, Tl, and Mg and at least one electrolyte selected from the group consisting of sodium sulfate, potassium sulfate, sodium chloride, and potassium chloride. Consequently, a coloring compound formed by the reaction of the aforementioned hexacyanoferrate (II) or hexacyanoferrate (III) with the aforementioned metal salt is deposited in the receding parts of micropores of an anodic oxide coating, with the result that the aluminum or aluminum alloy material is endowed with a durable color.

Abstract: The present invention provides a process for producing a perovskite-type oxide catalyst. The process comprises the steps of reacting an aqueous solution containing plural metal salts, such as chloride, sulfate, nitrate, etc., and an aqueous solution of a neutralizer such as alkali carbonate, alkali hydroxide, ammonia, etc., so as to cause coprecipitation of neutral salts and firing the coprecipitated salts to provide a perovskite-type oxide. At least one organic substance selected from the group consisting of cellulose, polyvinyl acetate, polyethylene, polystyrene, polypropylene, polyvinyl alcohol, starch, gelatin and saccharide is added prior to the firing step. The addition of the organic substance makes possible the attainment of a highly active perovskite-type oxide catalyst composed of very fine particles (primary particles).

Abstract: The specification discloses an alloy catalyst for oxidation of hydrogen which is prepared by heat treating a material comprising an amorphous alloy represented by the formula: Zr.sub.x Co.sub.(100-x) (wherein 10 atomic %.ltoreq..times..ltoreq.80 atomic %), according to the following three-steps in an oxidizing atomsphere: first heat-treatment step at a temperature at which the foregoing alloy stably exists as an amorphous single phase; second heat-treatment step at a temperature at which the alloy exists as a mixed phase of a metastable phase and an amorphous phase; and third-heat treatment step at a temperature at which the alloy is entirely transformed into a crystalline phase. The alloy catalyst of the present invention is a highly active catalyst for oxidation of hydrogen and exhibits a superior catalytic efficiency especially in catalytic combustion of hydrogen and in deoxidation and dehydrogenation of a gas mixture of hydrogen and oxygen.

Abstract: The invention provides a novel and improved method according to which the surface of a shaped article of aluminum or an aluminum-based alloy is provided with decorative streak patterns electrolytically engraved in the surface which can be subsequently colored to increase the decorative effect with uniform distribution over whole surface of the aluminum article. The method comprises first subjecting the anodically oxidized aluminum article to an anodic direct current electrolysis in an electrolytic solution containing a specified electrolyte and then carrying out a cathodic direct current electrolysis with the aluminum article and the counterelectrode kept as before in the same electrolytic solution as used in the first anodic direct current electrolysis with reversed polarity to give uniformly distributed streak patterns on the surface of the aluminum article.

Abstract: The corrosion resistance of an anodically oxidized surface film on aluminum articles is improved by sealing micropores and the like in such surface film with an aqueous sealing solution or dispersion containing siliceous material, such as silicic acid or a silicate, therein and thereafter overcoating the so-sealed surface with a select coating composition. The aqueous sealing solution is brought into contact with the aluminum article, such as by dipping the article into the solution and drying the so-coated article. Optionally, an electrical voltage may be applied through the sealing liquid and through the aluminum article during the sealing process. Further, in certain embodiments an electrical voltage may be applied through the sealing liquid before the liquid contacts the aluminum article. If desired, the surface of the aluminum article may be colored prior to sealing.

Abstract: A colored pattern imitating the grain of wood is formed on the surface of an article formed of an aluminum or its alloy by dipping the article in a coating bath floating a coating material in a multilinear pattern or multiannular pattern to form on the surface of the article a masking film in a pattern of the wood grain, subjecting the article to an oxide film application or etching and, after removal of the masking film, subjecting the article to an electrolytic coloring process.

Abstract: A colored pattern imitating the grain of wood is formed on the surface of an article formed of an aluminum or its alloys by dipping the article, after oxidation process, in a coating bath floating a coating material in a multilinear or multiannular pattern to deposit the coating material in a wood grain pattern on the surfaces of the article and applying thereto a finish coating.