| 摘要 |
PROBLEM TO BE SOLVED: To obtain the material having a low density, short mold release time and high hardness by reacting a specific polyisocyanate component, a polyether polyol component, water, a polyol component, optionally an additive, and a foaming agent. SOLUTION: A semirigid polyurethane foamed material is obtained by blending: (A) a polyisocyanate component having an NCO group content of 30-47 wt.%, a biuret structure, and contg. a toluene diisocyanate with an NCO group content of 33-47 wt.%; (B) a polyether polyol component having an average mol.wt. of 1,000-12,000 and at least two functionality values, and if necessary a solid content of 50 pts.wt. or less based on the whole component B wt.; if necessary (C) a polyol component having an average mol.wt. of 62-1,000 and at least two functionality values; optionally (D) an additive; (E) a foaming agent; and (F) water of 0.5-8 wt.% relative to the total wt. of components B through E, until the isocyanate index coming to 30-180, and then by reacting them. |
