SUBSTRATE TREATING AGENT FOR PRECOATED METAL SHEET, COATED SUBSTRATE-TREATED METAL SHEET COATED WITH THE SAME, AND PRECOATED METAL SHEET PRODUCED BY USING THE COATED SUBSTRATE-TREATED METAL SHEET

摘要

PROBLEM TO BE SOLVED: To provide: a new substrate treating agent suitably used for various types of precoated metal sheets; a coated substrate-treated metal sheet processed by coating the substrate treating agent ; and a precoated metal sheet produced using the coated substrate-treated metal sheet.;SOLUTION: The substrate treating agent for a precoated metal sheet includes, in water as solid contents, tannin or tannic acid, a silane coupling agent, and fine silica as well as a polyester resin including a sulfonic acid group or a sulfonate group as a substituent, and has a pH as a treating agent of 2.0-6.5. The substrate treating agent for a precoated metal sheet may include a phosphate compound in order to further improve the corrosion resistance of the precoated metal sheet.;COPYRIGHT: (C)2012,JPO&INPIT