申请人:Nippon Paint Automotive Coatings Co., Ltd.
公开号:EP3827904A1
公开(公告)日:2021-06-02
The present invention aims to provide a method for forming a multilayer coating film having good coating film smoothness. A method for forming a multilayer coating film, comprising a first aqueous coating composition application step of applying a first aqueous coating composition (A) to form an uncured first aqueous coating film; a second aqueous coating composition application step of applying a second aqueous coating composition (B) onto the uncured first aqueous coating film to form an uncured second aqueous coating film; a clear coating step of applying a clear coating composition (C) onto the uncured second aqueous coating film to form an uncured clear coating film; and a curing step of heat-curing at once these coating films to form a multilayer coating film, wherein the first aqueous coating composition (A) contains a water-dispersible polyurethane resin (a1) and a viscosity modifier (a2), and the second aqueous coating composition (B) contains water and an organic solvent as diluent components besides solid matters in a state of dilution to a coating viscosity.
本发明旨在提供一种形成具有良好涂膜平滑性的多层涂膜的方法。一种形成多层涂膜的方法,包括第一水性涂膜组合物涂敷步骤,在未固化的第一水性涂膜上涂敷第一水性涂膜组合物(A),形成未固化的第一水性涂膜;第二水性涂膜组合物涂敷步骤,在未固化的第一水性涂膜上涂敷第二水性涂膜组合物(B),形成未固化的第二水性涂膜;透明涂层步骤:在未固化的第二水性涂膜上涂布透明涂层组合物 (C),形成未固化的透明涂膜;以及将这些涂膜同时加热固化以形成多层涂膜的固化步骤,其中第一水性涂料组合物 (A) 包含水分散性聚氨酯树脂 (a1) 和粘度调节剂 (a2),而第二水性涂料组合物 (B) 除了稀释至涂料粘度的固体物质外,还包含作为稀释成分的水和有机溶剂。