| 摘要 |
PURPOSE: Provided is a soft polyurethane composition for reducing interfloor impact noise in a building, which has excellent noise protection effect and also shows waterproof property, heat insulation effect, chemical resistance, durability and mechanical strength. CONSTITUTION: The soft polyurethane composition comprises: a first composition of liquid soft polyurethane isocyanate obtained by reacting 100 parts by weight of prepolymer, 60-85 parts by weight of an isocyanate compound and 15-40 parts by weight of a polyol, the first composition having an NCO content of 15-25% and a viscosity of 200-1000 cps/23 deg.C; and a second composition of liquid resin premix obtained by reacting 100 parts by weight of resin premix, 90-95 parts by weight of a polyol, 2-5 parts by weight of a foaming agent, 1.0-3.0 parts by weight of a crosslinking agent, 0.5-1.5 parts by weight of a surfactant and 1.0-3.0 parts by weight of a catalyst, the second composition having a viscosity of 200-100 cps/23 deg.C. In the composition, the mixing ratio of the first composition to the second composition is 100:50-200 (wt/wt) so that the foaming and curing reaction can be accomplished at a molding density of 65-85 kg/m3 in 3-20 minutes.
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