PURPOSE: To produce a low-thermal conductivity rigid urethane foam suitalbe as a heat-insulating material for refrigerators, by adding a gas absorbent having a preadsorbed flon gas to a foamable stock solution and foaming the stock solution.
CONSTITUTION: One to twenty (1W20)wt% gas adsorbent, e.g., zeolite, having a preadsorbed flon gas, e.g., CCl2F2, is added to a foamable stock solution prepared by adding a foam stabilizer, a catalyst and a blowing agent to the principal components consisting of polyol, e.g., polyoxypropylene glycol, and an isocyanate, e.g., tolylene diisocyanate. The resulting solution is foamed.
EFFECT: It is possible to produce a rigid urethane foam freed from CO2, which has a high thermal conductivity and having uniform closed cells, about several hundreds μm in diameter.
SHIMIZU SEISABUROU
KANOU JIROU
YOSHIOKA HIROSHI
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