To provide a method for forming a coating film having a high hydrophilizing speed, developing stain resistance even before a rainfall, excellent in the stain resistance of a polished surface part and keeping stain resistance over a long period of time, and a car body using the method.
In the method for forming the coating film including a process for applying a hydrophylizing treatment agent to a base material having a coating film surface hydrophilic or capable of being made hydrophilic and drying the coated base material, the hydrophilizing treatment agent contains a hydrolysate of a silicate compound represented by formula (1) (wherein, (n) is an integer of 1-30, and groups R1 may be different and are 1-8C alkyl groups which have each a substituent or have no substituent), a nonionic surfactant, water and a hydrophilic organic solvent, and the nonionic surfactant has an alkylene oxide unit and HLB thereof is 10-15 and the amount thereof to water is 0.02-10 mass %.
AZUMAI TERUZO
TANABE HISANORI
URANO SATORU
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