| 摘要 |
PROBLEM TO BE SOLVED: To provide a hard polyurethane foam capable of cleaning the requirement for the second grade flame retardancy of JIS A-1321 which is a combustion test method for a building material and a construction method, and excellent in flame retardancy generating few fuming without spoiling a dimensional stability, and adhesive property, workability or the like by using water as a foaming agent, and to provide a production method of the same. SOLUTION: The production method of the phenol modified flame retardant polyurethane foam is characterized by reacting an acetylated novolak phenol resin whose hydroxyl group of 10-95% is acetylated, and polyisocyanate in the presence of a foaming agent. The phenol modified flame retardant polyurethane foam whose weight average molecular weight before acetylation is 250-1,000, is obtained. |
