| 摘要 |
PURPOSE: A heat-resistant modified isocyanate composition is provided to form a isocyanurate structure with high heat-resistance since the modified isocyanate composition has high coupling among isocyanate molecular, therefore the heat resistance gets remarkably improved, also is able to maintain the external appearance and the strength of polyurethane foam. CONSTITUTION: Polyurethane foam composition for pipe insulation comprises: poly mixture; modified isocyanate; catalyst; cross-linking agent; and blowing agent. The polyol mixture above comprises: polyether polyol in which 35-80wt.% hydroxyl value is 50-200 mg KOH/g; polyether polyol in which 25-70wt.% hydroxyl value is 200-400mg KOH/g; and polyether polyol in which 5-40wt.% hydroxyl value is 400-700 mg KOH/g. [Reference numerals] (AA) Start; (BB) End; (S10) Step of manufacturing a modified isocyanate; (S20) Step of manufacturing polyurethane blowing agent composite; (S30) Step of reaction |
