Toyo Aluminium Kabushiki Kaisha

Prime Polymer Co., Ltd.

Takao Mizoshita

Keita Nagano

Ikunori Sakai

Yoshio Sugimoto

Yusuke Umetani

Naoki Shoji

In order to provide a method of manufacturing an aluminum flake pigment having a small mean particle size as well as high brightness, a method of manufacturing an aluminum flake pigment including a step of flaking aluminum powder in an organic solvent with a grinder having grinding media, which grinding media contain steel ball grinding media formed by spherical media consisting of a material including steel and having diameters in the range of 0.3 mm to 1.0 mm, is provided. The mean particle size (D50) of this aluminum powder is preferably in the range of 1.0 to 10.0 &#x3bc;m. Further, this grinder is preferably a ball mill.

Method of manufacturing aluminum flake pigment, aluminum flake pigment obtained by the manufacturing method and grinding media employed for the manufacturing method

To provide a resin composition comprising a polypropylene resin composition and an aluminum flake pigment for use as an automotive resin composition, which is excellent in mechanical strength, physical properties and flowability, and enables to produce molded products showing good metallic appearance. A composition comprising a crystalline propylene/ethylene block copolymer, an elastomeric polymer and an inorganic filler is a preferred example of the polypropylene resin composition, and aluminum flakes surface-coated with a polymer containing as constituent units acrylic acid, an acrylic acid ester, epoxylated polybutadiene and divinylbenzene are preferred examples of the aluminum flake pigment.

Resin composition for automotive parts

An aluminum flake pigment suitable for use in metallic paints, metallic inks and the like is finely flaked in a grinder to include small aluminum flakes with a maximum dimension of not more than 10 &#x3bc;m, wherein these small aluminum flakes have a mean aspect ratio from 8 to 20. Overall, the aluminum flakes of the aluminum flake pigment preferably have a mean particle size from 3 to 20 &#x3bc;m. The grinder produces the aluminum flake pigment by flaking an aluminum powder in an organic solvent using steel ball grinding media having diameters of 0.3 to 1.0 mm.

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Yao, Japan

Takao Mizoshita