WATER DISPERSION OF HYDROXYPOLYURETHANE RESIN, GAS BARRIER FILM BASED ON THAT WATER DISPERSION, AND METHOD OF MANUFACTURING WATER DISPERSION OF HYDROXYPOLYURETHANE RESIN

To provide: a water dispersion which can be used as a film-forming resin for a water-based paint or coating agent, solves problems with the prior art where a hydroxypolyurethane resin is used, has satisfactory stability allowing practical use, and is excellent in dispersion stability even under an acidic condition; and a film based on the water dispersion excellent in gas barrier properties.SOLUTION: There is provided a water dispersion of a hydroxypolyurethane resin formed by phase-inversion emulsification so that the hydroxypolyurethane resin with particle size of 0.001 μm to 0.1 μm is dispersed in water. The hydroxypolyurethane resin has, in its structure, a repeating unit represented by general formula (1) comprising a chemical structure including a cationic group represented by general formula (11) for causing phase-inversion emulsification upon addition of water thereto.SELECTED DRAWING: None 【課題】水系塗料やコーティング剤の被膜形成用樹脂として使用可能であり、ヒドロキシポリウレタン樹脂を利用した場合の従来技術の課題を克服し、実用化が可能な良好な安定性を有し、さらに、酸性条件下でも分散安定性に優れる水分散体を提供すること、及び、該水分散体を使用し、ガスバリア性に優れたフィルムを提供すること。【解決手段】転相乳化されて、水中に、ヒドロキシポリウレタン樹脂が０．００１μｍ〜０．１μｍの粒子径にて分散してなる水分散体であり、前記ヒドロキシポリウレタン樹脂が、その構造中に、一般式（１）で示される、水を加えて転相乳化させるための一般式（１１）で表されるカチオン性基を含む化学構造からなる繰り返し単位を有してなるヒドロキシポリウレタン樹脂の水分散体。【選択図】なし