POLYMER-DISPERSED POLYOL AND PRODUCTION OF RIGID POLYURETHANE FOAM

摘要

PROBLEM TO BE SOLVED: To obtain a polymer-dispersed polyol having good dispersion stability, low viscosity and a high hydroxyl value by polymerizing a monomer having a polymerizable unsaturation in a polyol containing a polyether polyol having a specified composition and having an average hydroxyl value in a specified range. SOLUTION: A polyhydric alcohol such as glycerol and a cyclic ether such as ethylene oxide are subjected to an addition reaction to obtain a polyol comprising a polyether polyol which has an average hydroxyl value of 200-800 mgKOH/g and at least 5 wt.% of which has a hydroxyl value of 85 mgKOH/g or below and an oxyethylene content of 40 wt.% or above. A mixture of polymerizable-unsaturation-containing monomers such as 20-90 wt.% acrylonitrile and 10-80 wt.% styrene is polymerized in this polyol. A polyol comprising 0.8 wt.% or above polymer-dispersed polyol and 0.1-wt.% or above polymer microparticles and a polyisocyanate are reacted in the presence of a foam stabilizer, a catalyst and a blowing agent to obtain a rigid foam.