| 摘要 |
PROBLEM TO BE SOLVED: To obtain a modified polyisocyanate composition for a rigid polyurethane foam having excellent low-temperature storage stability, dimensional stability, adhesion, etc., and to provide a method for producing the rigid polyurethane foam. SOLUTION: This modified polyisocyanate composition for a rigid polyurethane foam is obtained by reacting (A) a polyphenylene polymethylene polyisocyanate containing 20-70 mass % of diphenylmethane diisocyanate with (B) an active hydrogen group-containing polysiloxane. In the above modified polyisocyanate composition, the weight ratio of the components (A): (B) is 0.0001-0.1 and the active hydrogen of the component B is selected from hydroxyl group, amino group and mercapto group and has 100-5,000 active hydrogen equivalents. The method for producing the rigid polyurethane foam comprises using the above modified polyisocyanate composition as the polyisocyanate. |
