Dipsol Chemicals Co., Ltd.

Honda Motor Co., Ltd.

Tadahiro Ohnuma

Manabu Inoue

Tomitaka Yamamoto

Tsutomu Miyadera

Go Sato

Hitoshi Sakurai

Toshiki Inomata

Disclosed is an electric Al&#x2014;Zr alloy plating bath containing an aluminum halide (A), one or more compounds (B) selected from the group consisting of N-alkylpyridinium halides, N-alkylimidazolium halides, N,N'-alkylimidazolium halides, N-alkylpyrazolium halides and N,N&#x2032;-alkylpyrazolium halides, and a zirconium halide (C). The molar ratio between the aluminum halide (A) and the compounds (B) is from 1:1 to 3:1. The electric Al&#x2014;Zr alloy plating bath further contains an aromatic organic solvent (D), an organic polymer (E) and one or more additives (F) selected from brightening agents.

Electric Al&#x2014;Zr alloy plating bath using room temperature molten salt bath and plating method using the same

To provide a barrel electroplating method which is less prone to bare spots and adhesion failure such as blisters and peeling, and which makes it possible to obtain uniform plated coatings free from burnt deposits and poor brightness, irrespective of the amount of workpieces. The present invention provides a method for performing barrel electroplating by use of an aluminum or aluminum alloy plating bath, the method comprising rotating, swinging, or vibrating an anode () placed inside a barrel () receiving workpieces, and simultaneously rotating, swinging, or vibrating the barrel, with a voltage being applied between the anode and a cathode provided on an inner wall surface of the barrel.

Aluminum or aluminum alloy barrel electroplating method

Disclosed herein is an electric Al or Al alloy plating bath which comprises (A) an aluminum halide; (B) one kind of compound or at least two kinds of compounds selected from the group consisting of N-alkylpyridinium halides, N-alkylimidazolium halides, N,N'-alkylimidazolium halides, N-alkyl-pyrazolium halides, N,N&#x2032;-alkylpyrazolium halides, N-alkylpyrrolidinium halides and N,N-alkyl-pyrrolidinium halides; and (C) a high boiling point aromatic hydrocarbon solvent, wherein the molar ratio of the aluminum halide (A) to the compound (B) ranges from 1:1 to 3:1 and the flash point of the plating bath is not less than 50&#xb0; C. The plating bath never involves any risk of causing an explosion, can be handled industrially with safety and can provide a smooth and fine Al of Al alloy plated film. Moreover, the resulting film has high resistance to corrosion even when it does not contain any chromium and therefore, it is quite suitable from the viewpoint of the environmental protection and it can thus be used in a wide variety of applications including the plating of parts for motorcars, and the plating of parts for electrical appliances.

Electric Al or Al alloy plating bath using room temperature molten salt bath and plating method using the same

A method for forming a rust proof film on a metal substrate comprising the step of immersing the metal substrate in a liquid rust proof film-forming composition which comprises (A) an oxidative substance, (B) a silicate and/or silicon dioxide and (C) at least one member selected from the group consisting of metal cations of Ti, Zr, Ce, Sr, V, W and Mo; and oxymetal anions and fluorometal anions thereof.

Method for forming a rust proof film

A composition for water-repellent treatment of zinc and zinc alloys which comprises a non-ionic polymeric compound having both hydrophilic and hydrophobic groups in the molecule, a polyacrylic acid salt and a balance of water. The composition can be used in a method for water-repellent treatment of zinc and zinc alloys which comprises the steps of immersing zinc or zinc alloys which has been subjected to a conversion treatment, then washing it with water and drying the same. The use of the water-soluble composition for water-repellent treatments permits considerable reduction of the contact area between the repellent-treated metal material and moisture which becomes a cause of corrosion under the corrosive environment in which water and oxygen coexist and this accordingly results in the improvement in the corrosion-resistance of the metal material.

Water-soluble composition for water-repellent treatments of zinc and

A liquid rust proof film-forming composition comprises (A) an oxidative substance, (B) a silicate and/or silicon dioxide and (C) at least one member selected from the group consisting of metal cations of Ti, Zr, Ce, Sr, V, W and Mo; and oxymetal anions and fluorometal anions thereof. The composition can be used in a method for forming a rust proof film on a metal substrate which comprises the step of immersing the metal substrate in the composition. The composition and the methods form an excellent rust proof film on the surface of metal substrates without using any chemical substance harmful to environment such as hexavalent chromium.

Liquid rust proof film-forming composition and rust proof film-forming

A tin-zinc alloy electroplating bath comprises an amphoteric surfactant, a water-soluble stannous salt, a water-soluble zinc salt and a balance of water. When the tin-zinc alloy plating bath of the present invention is used, the formed coating film comprises a uniform alloy composition even in case where the current density varies over a wide range. Therefore, the coating film having the uniform alloy composition can be formed even on the substance having a complicated shape and the chromate treatment becomes satisfactory. As a result, the effect of the coating is improved, the resultant product is stable and the productivity is improved. Thus the tin-zinc alloy coating film having a high quality can be provided.

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Tokyo, Japan

Tadahiro Ohnuma