POSTTREATING AGENT FOR PHOSPHATE TREATED FILM ON METALLIC SURFACE, COATED STEEL SHEET OBTAINABLE BY USING POSTTREATING AGENT, AND ITS PRODUCTION METHOD

摘要

PROBLEM TO BE SOLVED: To provide a coated steel sheet excellent in corrosion resistance and hydrophilic properties and also free from problems from the aspect of environmental preservation. SOLUTION: This posttreating agent for a phosphate treated film on a metallic surface contains (A) at least one kind of titanium-containing water based solutions selected from (A1) a titanium-containing water based solution obtainable by bringing a titanium monomer containing a group made into a hydroxyl group by being hydrolyzed and/or the low condensate thereof into reaction with a hydrogen peroxide solution and (A2) a titanium-containing water based solution obtainable by bringing a titanium monomer containing a group made into a hydroxyl group by being hydrolyzed and/or the low condensate thereof into reaction with a hydrogen peroxide solution in the presence of a titanium oxide sol and (B) at least one kind of metal selected from titanium halide, titanium halide salt, zirconium halide and zirconium halide salt or silicon halide.