Honda Motor Co., Ltd.

Basf Coatings Gmbh

Kyohei Homma

Takeshi Ogawa

Hisayuki Nakashima

Yusuke Kurata

Yusuke Yagi

Disclosed is a method for forming a multilayer coating film, including applying a first and second aqueous base coat, and a clear coat to an object, and thereafter simultaneously heating and curing the three-layer coating film. The first aqueous base coat includes a water-soluble or water-dispersible polyurethane resin having a glass transition temperature of &#x2212;20&#xb0; C. or below and a weight average molecular weight of 30,000 to 500,000, and a crosslinkable resin having a weight average molecular weight of 600 or more. The first aqueous base coat-coated film has a breaking strength of 2050 N/cm2 or more and a loss tangent (tan &#x3b4;) at &#x2212;20&#xb0; C. of 0.075 or more. The migration amount of a melamine resin from the second aqueous base coat-coated film layer to the first aqueous base coat-coated film layer is within 3% by mass of a total resin solid content of the first aqueous base coat.

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Yokohama, Japan

Kyohei Homma