| 摘要 |
PURPOSE:To obtain a flexible polyurethane foam slab excellent in impact resilience, tensile strength, tear strength, etc., according to a one-shot method by using a specific polyisocyanate component, an active hydrogen compound, an additive and water as a foaming agent. CONSTITUTION:The flexible polyurethane foam slab is produced by reacting (A) a polyisocyanate component composed of a mixture of (A1) diphenylmethane diisocyanate (MDI) containing 5-50wt.% total amount of the 2,2'- and 2,4'-isomers with (A2) polymeric MDI having 30-60wt.% di (MDI) content and <=30wt.% total amount of the 2,2'- and 2,4'-isomers in the di at (2.5/7.5) to (8/2) mixing weight ratio of the components (A1)/(A2) with (B) a polyol component composed of an active hydrogen compound (e.g. polyether polyol), water as a foaming agent and an additive (e.g. a catalyst or a foam stabilizer) according to a one- shot method. The amount of the MDI in the mixture is 50-90wt.% and the total amount of the 2,2'- and 2,4'-isomers in the MDI is 5-50wt.% in the polyisocyanate component (A). |
