UNDERLAYER TREATMENT SOLUTION, METHOD FOR MANUFACTURING ORGANIC COATED GALVANIZED STEEL PIPE USING THE SAME AND ORGANIC COATED GALVANIZED STEEL PIPE

摘要

PROBLEM TO BE SOLVED: To provide an underlayer treatment solution capable of forming an underlayer allowing increase of adhesion to an organic resin layer even on a galvanized layer.SOLUTION: The underlayer treatment solution comprises: an aqueous solvent; a zirconium compound having a concentration of 0.05-10.50 mass% in terms of metal Zr; a vanadium compound having a concentration of 0.004-0.400 mass% in terms of metal V; an ammonium phosphate having a concentration of 0.07-7.50 mass% in terms of phosphate ions; a silane coupling agent having a concentration of 0.1-10 mass% in terms of a solid content and/or a hydrolytic condensate thereof; and a silica compound having a concentration of 0.2-10 mass% in terms of a solid content and has a pH of 8-12.SELECTED DRAWING: None