COATING METHOD AND COATED ARTICLE OBTAINED BY THE SAME

摘要

A coating method for forming a laminated coating film including: preparing a thermosetting coating material as a lower layer-coating material, an intermediate layer-coating material, and as an upper layer-coating material; forming an uncured laminated coating film by applying the lower layer-coating, the intermediate layer-coating, and the upper layer-coating materials on the base material using a wet-on-wet technique; and simultaneously curing the lower layer-coating, the intermediate layer-coating, and upper layer-coating materials by baking the uncured laminated coating film. In the preparation step, the lower layer-coating, the intermediate layer-coating, and the upper layer-coating materials are selected so a sum of an absolute value of a difference in shrinkage ratio between the lower layer-coating and the intermediate layer-coating materials and an absolute value of a difference in shrinkage ratio between the intermediate layer-coating and the upper layer-coating materials at the late stage of the baking is 3.0% or smaller.

主权项

1. A coating method for forming a laminated coating film including a lower layer formed on a base material, an intermediate layer formed on the lower layer, and an upper layer formed on the intermediate layer, the method comprising:
a preparation step of preparing a thermosetting coating material as a lower layer-coating material for forming the lower layer, preparing a thermosetting coating material as an intermediate layer-coating material for forming the intermediate layer, and preparing a thermosetting coating material as an upper layer-coating material for forming the upper layer; a formation step of forming an uncured laminated coating film by applying the lower layer-coating material, the intermediate layer-coating material, and the upper layer-coating material on the base material using a wet-on-wet technique; and a baking step of simultaneously curing the lower layer-coating material, the intermediate layer-coating material, and the upper layer-coating material by subjecting the uncured laminated coating film to a baking treatment, wherein in the preparation step, the lower layer-coating material, the intermediate layer-coating material, and the upper layer-coating material are selected so that a sum of an absolute value of a difference in shrinkage ratio between the lower layer-coating material and the intermediate layer-coating material at a late stage of the baking in the baking step and an absolute value of a difference in shrinkage ratio between the intermediate layer-coating material and the upper layer-coating material at the late stage of the baking in the baking step is 3.0% or smaller.