| 摘要 |
PROBLEM TO BE SOLVED: To obtain a polyurethane-based aqueous dispersion and the corresponding water-based coating material having the ability to form a coating film excellent in high-level bending processability, coin scratch resistance and corrosion resistance. SOLUTION: This water-based dispersion comprises (A) a polyurethane resin prepared by reaction between (a) a polyester diol composed of acid component 20-100 mol% of which is an aromatic dicarboxylic acid and 10-70 wt.% of repeating unit, of either one of bisphenol A, bisphenol F or cyclohexane skeleton, (b) an organic diisocyanate compound, and as necessary (c) a chain extender <500 in molecular weight, (B) a water-soluble organic compound <=250 deg.C in boiling point, (C) water, and (D) a neutralizing agent.
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