| 摘要 |
A water-soluble polyurethane/epoxy resin composition is provided to replace solvent type polyurethane, to allow re-emulsion, and to improve storage stability, water resistance after drying, and mechanical properties. A method for preparing a water-soluble polyurethane compound of the formula includes the steps of: (a) reacting diisocyanate with ether or ester-based polyols having a weight average molecular weight of 500-6,000 and glycol comprising ionizable carboxylic acid to prepare a water-soluble polyurethane prepolymer, and neutralizing the prepolymer with a neutralizer; (b) reacting epoxy groups of an epoxy resin with a silane compound to prepare modified epoxy resins obtained by substituting the terminals of the epoxy with silane groups, or a mixture thereof; and (c) mixing the neutralized polyurethane prepolymer with the modified epoxy resins and mixture thereof, dispersing the mixture in water, stirring the dispersion, thereto adding a chain extender to prepare the water-soluble polyurethane compound through chain extension.
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