Toyota Jidosha Kabushiki Kaisha

Kansai Paint Company, Ltd.

Nippon Paint Compnay, Ltd.

Nippon Paint Automotive Coatings Co., Ltd

Yoshinori Narita

Keiji Ambo

Masako Hase

Hisaki Tanabe

Yukihiro Ikeura

Hideaki Tsujioka

Akira Yamazaki

Kazuki Matsubara

Junji Shimada

Takayuki Kawabata

Hiroshi Nishinaka

Mirei Kato

The coating film formed on an automobile body has softness during a film formation even on a thermally expandable/shrinkable base, and the cured film has an excellent appearance. Provided is a method for forming a multilayer coating film, the method comprises: applying an aqueous intermediate coating composition and preheating the applied composition at 60 to 90&#xb0; C. to form an uncured film; preheating to form an uncured base coating film and a clear coating film; and baking and curing these uncured films to form a multilayer coating film, wherein the aqueous intermediate coating composition comprises (a) an acrylic resin emulsion having a specific properties, and (b) a film formation auxiliary agent that is a fatty acid diester compound having a boiling point of 280&#xb0; C. to 350&#xb0; C., and a cured film comprising (a) and (b) at a mass ratio of 3:1 has a rupture elongation of 1% or more.

Method for forming multilayer coating film

A method for forming a multilayer coated film on an electrodeposition-coated alloyed hot-dip galvanized steel plate include step (1) of applying an aqueous intermediate coating composition (X), step (2) of applying an aqueous base coating composition (Y), step (3) of applying a clear coating composition (Z) containing an epoxide, and step (4) of heat-curing each coated film. The coating composition (X) contains a hydroxyl group-containing acrylic resin (A), a polyurethane resin (B), a hydroxyl group-containing polyester resin (C), a melamine resin (D), and an active methylene-blocked polyisocyanate compound (E). The ratio of (A) to (B) is controlled to a specific range, and an elongation at break, Young's modulus and Tukon hardness of the coated film of the coating composition (X) are controlled to specific ranges.

Method for forming multilayer coated film

An automotive clear coating composition includes a hydroxyl group-containing acrylic resin obtained using hydroxyalkyl(meth)acrylate having a hydroxyalkyl group having 4-9 carbon atoms as at least a part of its monomer; and a polyfunctional isocyanate compound in which at least a part thereof is an isocyanurate type isocyanate compound. The prepared composition has 25 to 50 mass % of a soft segment part with respect to a total solid content of such acrylic resin and the polyfunctional isocyanate compound, and a ratio of a soft segment part derived from a lactone-containing monomer with respect to the total solid content of such acrylic resin and the polyfunctional isocyanate compound of not more than 4.5 mass %. A cured coating film has a dynamic glass transition temperature within a range of 30 to 60&#xb0; C. The soft segment part is represented by &#x2014;CH)&#x2014; wherein n represents an integer of 4 or more.

Clear coating composition for an automobile and method of forming a multi-layer coating film using the same

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Toyota, Japan

Yoshinori Narita