| 摘要 |
PROBLEM TO BE SOLVED: To provide a water-based metal surface treating composition for forming a lubricating resin film excellent in corrosion resistance, film adhesion, and scratch resistance. SOLUTION: This composition comprises (a) a water-based urethane resin which is a water-based urethane resin having a bisphenol skeletons and carboxyl groups in the resin skeleton and has an average molecular weight of 3,000 or above and in which the content of nitrogen taking part in the reaction of an isocyanate during the synthesis of the resin is in the range of 2-13 wt.%, and the ratio, nitrogen atoms of urea bonds/nitrogen atoms taking part in the reaction of the isocyanate, i.e., the ratio of the nitrogen atoms taking part in urea bonds to the nitrogen atoms taking part in the reaction of the isocyanate during the synthesis of the resin, is in the range of 10/100 to 90/100, (b) a curing agent, (c) silica, and (d) a polyolefin wax, and wherein the weight of the solids of components (a) and (b) is 50-95% based on the total weight of solids (e), the equivalent ratio of the functional groups of component (b) to the equivalents of the carboxyl contained in the skeleton of component (a) is 0.10-1.00, the amount of the solids of component (c) is 3-40 wt.% based on the solids of component (e), and the amount of the solids of component (d) is 2-30% based on the total weight (e) of solids. |
