| 摘要 |
PROBLEM TO BE SOLVED: To provide a flexible polyurethane foam having an adequate hardness and excellent aging resistance in wet heat, and further to provide a toner-sealing material obtained by using the polyurethane foam, and having sufficient sealing properties. SOLUTION: This flexible polyurethane foam is obtained by reacting a raw material for the foam comprising a polyisocyanate and a polyol. The polyol comprises a polyether polyol in which the number of the functional groups is 2, and which has 500-1,800 number average molecular weight, and a polyester polyol in which the number of the functional groups is 3, and which has 1,500-4,000 number average molecular weight. Preferably, a low molecular weight triol in which the number of the functional groups is 3 and which has 250-1,400 number average molecular weight is included as the polyol component. The toner-sealing material comprises the specific flexible polyurethane foam. |
