| 摘要 |
PROBLEM TO BE SOLVED: To provide an inexpensive heat insulation material bringing out a favorable heat insulation function by mixing resin-premix liquid including polyol as a chief component with isocyanate liquid and foaming it by spraying and forming a specified percent of closed cells. SOLUTION: This heat insulation material is made of a rigid polyurethane foam having a closed cell ratio of 10-50%. A resin-premix A liquid including polyol as a chief component and an isocyanate B liquid are sprayed by a thermal airless spraying foaming machine. Low boiling point-chlorofluorocarbon or the like is added to the A liquid on foaming. The raw liquid characteristic obtained by mixing the liquid A with the liquid B is adjusted so that the cream time is 5-12 sec and the rise time is 20-40 sec in hand mixing at 5 deg.C. A polyurethane foaming material forming a high close cell ratio and a polyurethane foaming material forming a high open cell ratio are adjustably blended at an appropriate ratio. In this way, a heat insulation material which is excellent in heat insulation and dimensional stability, and light-weight, can be costlessly formed.
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