| 摘要 |
PURPOSE: A polyurethane resin composition for a mid sole is provided which has low density of a mid sole being 0.20-0.30 g/cc and excellent physical properties thereof. CONSTITUTION: A polyurethane resin composition comprises a polyol mixture which comprises 80-90 wt% of polyols, 0.5-2.5 wt% of water, 0.1-5.0 wt% of an expandable micro spherical organic filler, and a prepolymer containing terminal of isocyanate groups. Preferably the polyols consist of 80-100 wt% of polyester polyol and 0-20 wt% of polyether polyol, of which functionality is 1.8-5 each, the average functionality of the mixture is 2.0-2.5, and the average molecular weight of the polyols is 500-5,000. The reactivity ratio (a molar ratio of -NCO/-OH) of the prepolymer and the polyols mixture is 0.90-1.1, and the expandable micro spherical organic filler is one that the shell consisting of a copolymer of acrylonitrile and vinylidene chloride, surrounds isobutane. |
