An object of the present invention is to provide a method for forming a multilayer coating film, capable of achieving excellent curability under low-temperature, short-time conditions, and forming a multilayer coating film having excellent chipping resistance and an excellent finished appearance. This method comprises sequentially applying an aqueous first colored coating composition (X), an aqueous second colored coating composition (Y), and a clear coating composition (Z) to a substrate, and simultaneously bake-curing the resulting multilayer coating film. In this method, the aqueous first colored coating composition (X) comprises an aqueous film-forming resin (A) and a specific blocked polyisocyanate compound (B), and the clear coating composition (Z) comprises a hydroxy-containing acrylic resin (K) having a hydroxy value in a specific range, a polyisocyanate compound (L), and an organometallic catalyst (M) containing a metal compound (M1) selected from a specific range and an amidine compound (M2).
本发明的目的是提供一种形成多层涂膜的方法,该方法能够在低温、短时间条件下实现优异的固化性,并形成具有优异抗崩角性和出色成品外观的多层涂膜。该方法包括依次将
水性第一有色涂层组合物(X)、
水性第二有色涂层组合物(Y)和透明涂层组合物(Z)涂覆到基底上,并同时对所得到的多层涂膜进行烘烤固化。在该方法中,
水性第一有色涂层组合物(X)包括
水性成膜
树脂(A)和特定封端的多
异氰酸酯化合物(B),透明涂层组合物(Z)包括羟值在特定范围内的含羟基
丙烯酸树脂(K)、多
异氰酸酯化合物(L)和有机
金属催化剂(M),其中有机
金属催化剂(M)包含选自特定范围的
金属化合物(M1)和脒化合物(M2)。