| 摘要 |
The present invention discloses a viscoelastic sound-absorbing polyurethane foam and a method for preparing the same, the foam being prepared by reacting a polyisocyanate composition and an isocyanate reactive component. The isocyanate reactive component comprises, based on the weight of mixed polyethers, 30-80 wt % of (bii) a copolyol of epoxypropane-epoxyethane, or a conjugate thereof, wherein the content of oxy-ethylidene unit is 5-35 wt %; 2-20 wt % of (biii) a copolyol of epoxypropane-epoxyethane, or a conjugate thereof, wherein the content of oxy-ethylidene unit is 70-100 wt %; and 20-70 wt % of (biv) a copolyol of epoxypropane-epoxyethane, or a conjugate thereof, wherein the content of oxy-ethylidene unit is 0-20 wt %. The sound-absorbing foam of the present invention has a ball rebound rate of 15-30% and good sound absorption performance. |
| 主权项 |
1. A sound-absorbing viscoelastic polyurethane foam, characterized in that the foam is prepared from a reaction system comprising the following components:
(a) a polyisocyanate composition comprising 0-5 wt % of toluene diisocyanate, based on the total weight of the polyisocyanate composition, wherein the number average functionality of isocyanate groups in the polyisocyanate composition is 2-2.4 and the NCO content is 20-35 wt %; (b) an isocyanate-reactive component comprising: (bi) water, in an amount of 2-5 wt % of the mixed polyethers' weight; (bii) a copolyol of epoxypropane-epoxyethane or a conjugate thereof, wherein the content of oxy-ethylidene units is 5-35 wt % with an average functionality of 2-4 and an average hydroxyl value of 20-65 mgKOH/g, which is in an amount of 30-70 wt % of the mixed polyethers' weight; (biii) a copolyol of epoxypropane-epoxyethane or a conjugate thereof, wherein the content of oxy-ethylidene units is 70-100 wt % with an average functionality of 2-4 and an average hydroxyl value of 20-200 mgKOH/g, which is in an amount of 2-20 wt % of the mixed polyethers' weight; (biv) a copolyol of epoxypropane-epoxyethane or a conjugate thereof, wherein the content of oxy-ethylidene units is 0-20 wt % with an average functionality of 2-5 and an average hydroxyl value of 180-830 mgKOH/g, which is in an amount of 20-65 wt % of the mixed polyethers' weight; (bv) a chain extender and/or a cross-linking agent, in an amount of 0-10 wt % of the mixed polyethers' weight; wherein the mixed polyethers are mixtures of component (bii), component (biii) and component (biv); (c) a surfactant, in an amount of 0-1 wt % of the mixed polyethers' weight; (d) a catalyst, in an amount of 0-3.5 wt % of the mixed polyethers' weight; and (e) an optional additive, comprising one or two or more of color pastes, internal mold release agents, flame retardants, fillers, antistatic agents, perfumes, antioxidants, light stabilizers, mineral oils and antimicrobial agents; wherein the reaction system has an isocyanate index of 0.6-0.9, preferably 0.6-0.8, more preferably 0.6-0.75. |
