| 摘要 |
PURPOSE: Micro cellular elastomeric polyurethane foams are provided to be easily processed through wide density, and to have a high hard block -content, not having high hardness. CONSTITUTION: Micro cellular elastomeric polyurethane foams are manufactured from a reaction mixture such as a polyisoyanate component, a polyol composition, a chain extender, water and optionally a cross linking agent. The polyisoyanate component includes more than 85 weight percent of 4.4'-diphenylmethane diisocyanate or a variant thereof. The polyol composition includes more than one polyoxyalkylene polyol for including oxyethylene residue, The polyol composition has an average nominal hydroxyl functionality of 2 to 6, an average hydroxyl equivalent with more than 1300, and an average oxyethylene content of 50 to 85 weight percent. The chain extender has an average hydroxyl equivalent with 15 to 250. A hardblock is more than 45 weight percent.
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