| 摘要 |
PROBLEM TO BE SOLVED: To obtain a coating composition which can form a coating film satisfactory in processability, scratch resistance, high-temperature humidity resistance, and corrosion resistance by mixing an amine-modified epoxy resin with a blocked polyisocyanate compound, a strontium chromate pigment, a white titanium pigment, and other pigment in a specified ratio. SOLUTION: This composition comprises 70-95 pts.wt. amine-modified epoxy resin having a number-average molecular weight of 2,000-12,000, 5-30 pts.wt. blocked isocyanate compound, 30-100 pts.wt. strontium chromate pigment, 20-130 pts.wt. white titanium pigment, 0-10 pts.wt. other pigments, the total of the pigments being 60-180 pts.wt. The amine-modified epoxy resin can be obtained by reacting a mixture comprising 70-100 wt.% bisphenol-derived epoxy resin having a number-average molecular weight of 350-4,500 and an epoxy equivalent of 170-4,000 g/equivalent and 0-30 wt.% polysulfide-modified epoxy resin having a number-average molecular weight of 350-4,500 and an epoxy equivalent of 170-4,000 g/equivalent with a polyfunctional amine in an epoxy group/active hydrogen equivalent ratio of 1/(1.1-1.8).
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