| 摘要 |
PURPOSE:The titled elastomer excellent in elastic recovery and durability, obtained by mixing a specified NCO-terminated prepolymer with a blowing agent. CONSTITUTION:A blowing agent is added to an NCO-terminated prepolymer obtained by reacting an aromatic group-containing polyester-polyol with an organic polyisocyanate. The blowing agent used is water or its mixture with a hydrophilic organic chain extender. The water plays both a role of a blowing agent and a role of a chain extender, so that the amount of water as a blowing agent depends on the % NCO of an NCO-terminated prepolymer used, the density of the desired cellular polyurethane elastomer, etc. Examples of the hydrophilic organic chain extenders used, include ethylene glycol and 1,3-propylene glycol. The organic polyisocyanate which can be used suitably is 1,5-naphthylene diisocyanate. |
