| 摘要 |
PROBLEM TO BE SOLVED: To provide an aqueous resin composition having excellent freezing-melting stability and low-temperature film-forming properties though having a low minimum film-forming temperature (MFT) and forming a coated film having excellent warm water whitening, blocking, weather, and rain streak stain resistances, gloss, etc. SOLUTION: The aqueous resin composition contains an emulsion containing heterophasic structural particles obtained by a multistage emulsion polymerization method. The outermost phase of the heterophasic structural particles is formed of an emulsion copolymer containing an ethylenically unsaturated monomer unit having a polyethylene glycol chain and/or a polypropylene glycol chain and a polymerizable photostable monomer unit and has -50 to 15°C Tg. An emulsion copolymer forming at lease one phase of the inner phases of the heterophasic structural particles contains an ethylenically unsaturated monomer unit having a carboxy group and has 30-150°C Tg. The difference between the Tg of the emulsion copolymer forming the outermost phase of the heterophasic structural particles and the Tg of the emulsion copolymer forming at least one phase of the inner phases is 30-135°C. COPYRIGHT: (C)2004,JPO
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