| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for producing a polyurethane foam usable for a heat insulating material or the like by which a mechanical strength of the polyurethane foam obtained by using water as a blowing agent is improved, and swelling of the foam at the time of foaming is prevented by carrying out an addition polymerization reaction in combination with a urethanation reaction of a specific organic isocyanate with an active hydrogen compound. SOLUTION: When (A) an active hydrogen compound is reacted with (B) an organic isocyanate in the presence of (C) a blowing agent consisting of water, (D) a urethanation catalyst, and (E) optional other additives, a modified organic isocyanate having (B1) an additionally polymerizable functional group obtained by reacting (a) an active hydrogen-containing group of a compound having an additionally polymerizable functional group and the active hydrogen- containing group, with (b) an isocyanate group of an excessive organic polyisocyanate is used at least a part of the component B, and a polyurethane- forming reaction is carried out in combination with the polymerization of the additionally polymerizable functional group. |
