| 摘要 |
PROBLEM TO BE SOLVED: To provide a high molecular weight aqueous emulsion excellent in storage stability, etc.SOLUTION: An aqueous emulsion is obtained by reacting together 2-8 wt.% of an isocyanate, 7-15 wt.% of a polyol, 0.3-1.0 wt.% of a hydrophilic carboxyl monomer having a polyol and 0.1-2.0 wt.% of a hydroxy-containing acrylate to form a polyurethane prepolymer of an NCO content of about 2-8% having unsaturated double bonds, adding 0.3-1.0 wt.% of an alkali neutralizer, water-dispersing in 25-40 wt.% of pure water, adding 0.1-0.5 wt.% of a chain extender to form an ethylenic unsaturated water-dispersible polyurethane, adding 40-60 wt.% of deionized water and 20-30 wt.% of an alkyl methacrylate or an alkyl acrylate monomer to the ethylenic unsaturated water-dispersible polyurethane to form a reaction system and emulsion-polymerizing the reaction system with 0.1-2.0 wt.% of a persulfate initiator so as to conduct graft copolymerization of the water-dispersible polyurethane resin with the acrylate monomer. |
