| 摘要 |
PURPOSE:To obtain a rigid expanded synthetic resin in good workability without causing any environmental pollution etc., by reacting an active hydrogen compound with a polyisocyanate compound in the presence of a blowing agent comprising a specified azodicarboxylic acid derivative. CONSTITUTION:An active hydrogen compound (A) having at least two active hydrogen functional groups reactive with an isocyanate group e.g., polyether polyol) is reacted with a polyisocyanate compound (B) (e.g., tolylene diisocyanate) in the presence of a blowing agent (C) comprising an azodicarboxylic acid derivative of the formula R1R2NCON=NCONR3R4 (wherein R1, R2, R3 and R4 are each H, a 1-10 C saturated or unsaturated alkyl) (e.g., azobisisobutyramide) to obtain an expanded synthetic resin. An open-cellular rigid urethane foam can be easily produced by using a combination of component C with a low-boiling (halo)hydrocarbon or the like as said blowing agent. |
