Harima Chemicals, Incorporated

Other

Denso Corporation

Sumitomo Light Metal Industries, Ltd.

Ichiro Taninaka

Shoei Teshima

Yoshiharu Hasegawa

Yuji Hisatomi

Akira Itoh

Taketoshi Toyama

Ken Muto

Ryoichi Sanada

Tomoaki Akazawa

Takashi Hatori

Koji Onouchi

Masaki Teruse

Kinya Yamamoto

Shouei Teshima

Tsutomu Usami

Hikaru Shibata

Yuji c/o Sumitomo Light Metal Industries Ltd Hisatomi

A paste composition for aluminum brazing of the invention contains 40 to 65% by weight of a metal powder for brazing (a), 5 to 35% by weight of a fluoride type flux (b), 1 to 10% by weight of a methacrylic acid ester type polymer (c), and 10 to 40% by weight of an organic solvent (d); and the component (d) is a hydrocarbon type organic solvent having no aromatic ring and no hydroxyl group and the composition is in a paste-like state having a viscosity of 6,000 to 200,000 mPa&#xb7;s at 23&#xb0; C. and accordingly, the storage stability and applicability (practically, discharge property and pressure stability by using a dispenser) and brazing property can be improved in good balance.

Paste composition for aluminum brazing

An aqueous aluminum brazing composition containing an organic binder and a zinc-based flux which prevents the precipitation of the zinc-based flux having a large specific gravity while securing an excellent brazeability. The thixotropic index of the brazing composition is adjusted to 1.01-1.20 by adding a (meth)acrylic acid/(meth)acrylate copolymer emulsion to the brazing composition as a precipitation inhibitor in an amount of 0.03-1.50 wt % of 100 wt % of the brazing composition. Since the (meth)acrylic acid/(meth)acrylate copolymer emulsion is used as the precipitation inhibitor in a specific amount instead of other types of compounds used for a powder-containing paint, such as ultrafine particle silica, poly(meth)acrylate, or polyvinyl alcohol, the precipitation of the zinc-based flux can be prevented without impairing the brazeability.

Aqueous aluminum brazing composition, aluminum material coated with the brazing composition, brazing method using the aluminum material, and automotive heat exchanger manufactured by using the brazing method

The purpose of the present invention is provide a method of forming a flux layer on an aluminum plate member, wherein a heating step for drying after a spray-coating of a flux composition can be omitted. The invention relates to a flux layercomposed of solid constituents of 5-25 g/mformed on a surface of an aluminum plate member, by spray-coating a flux composition from a nozzleto the plate memberwith a thickness of 0.2-1.6 mm, which was press-molded and heated for degreasing in a heat-degreasing oven, while a temperature of the plate memberis kept from 120 to 180&#xb0; C. under the remaining heat after completing a heating step for degreasing, and naturally drying for volatilizing volatile constituents of the flux composition utilizing the remaining heat.

Method of forming a flux layer on an aluminum plate member

An aluminum extruded multi-cavity flat tube for use in an automotive heat exchanger having excellent brazing characteristics. At least one of the flat surfaces of said aluminum extruded multi-cavity flat tube is coated with a flux composition comprising a brazing flux and a synthetic resin based, as its main constituent, on a methacrylate homopolymer or a methacrylate copolymer or, alternatively, with a brazing composition comprising a brazing flux, brazing metals, and said synthetic resin. In a preferred embodiment, such a coating is provided by applying to a surface of an aluminum extruded multi-cavity flat tube, said compositions as added to an organic solvent and having a molecular structure wherein the atomic ratio of carbon to oxygen is between 2 and 3, by a roll-transfer printing technique.

Aluminum-extruded multi-cavity flat tube having excellent brazing characteristics for use in automotive heat exchanger and manufacturing method therefor

The present invention is a water-based binder used when manufacturing aluminum brazed products such as engine radiators, condensers for car air conditioners, and the like. The water-based binder is obtained by saponifying an ester methacrylate polymer that has an acid value and a glass transition temperature within specified ranges. In the presence of an alcohol that is water soluble and volatile and has a flash point higher than a specified temperature, the brazing composition, in which this binder and flux and the like are mixed, does not have the risk of catching on fire or exploding and also has excellent wettability and can be uniformly coated onto an aluminum material. Furthermore, when a binder in which polyoxirane or polyoxazoline is added as a sub component to this ester methacrylate polymer, which is the main component, the room temperature adhesion of the brazing composition onto the aluminum materials is further improved, and thickening of this composition during coating or storage is also prevented.

Water-base binder for aluminum material brazing, brazing composition, and method of brazing with the composition

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Kakogawa, Japan

Ichiro Taninaka