| 摘要 |
This invention relates to novel polyol blends, a process for the production of foam with very low resistance to air flow from certain polyol blends and to the resultant foams produced from certain polyol blends. The polyol blends comprise one or more monofunctional polyethers having a hydroxyl number of less than 28; one or more polyether polyols having a hydroxyl number of 20 to 240 and containing at least 50% of copolymerized oxyethylene; one or more polyether polyols having a hydroxyl number of 47 to 300 and containing from 5 to 40% of copolymerized oxyethylene; and optionally, one or more polyether polyols having a hydroxyl number of 10 to 45. This process of the invention comprises reacting one or more polyisocyanates, with an isocyanate-reactive component in the presence of at least one catalyst, at least one surfactant and at least one blowing agent. The isocyanate-reactive component comprises one or more monofunctional polyethers having a low hydroxyl number; one or more polyether polyols having a hydroxyl number of 20 to 240 and containing at least 50% of copolymerized oxyethylene; one or more polyether polyols having a hydroxyl number of 47 to 300 and containing from 5 to 40% of copolymerized oxyethylene; and optionally, one or more polyether polyols having a hydroxyl number of 10 to 45. |
| 主权项 |
1. A polyol blend comprising:
1) from 5 to 40% by weight, based on 100% by weight of said polyol blend, of one or more monofunctional polyethers having a hydroxyl number of less than or equal to 28 mg KOH/g; and containing from 2 to less than or equal to 20% of copolymerized oxyethylene, based on the total weight of said monofunctional polyether; 2) from 2 to 80% by weight, based on 100% by weight of said polyol blend, of one or more polyether polyols having a functionality of from 2 to 8, a hydroxyl number of from 20 to 240 mg KOH/g and containing at least 50% of copolymerized oxyethylene, based on the total weight of said polyether polyol 2); 3) from 10 to 70% by weight, based on 100% by weight of said polyol blend, of one or more polyether polyols having a hydroxyl number of from 47 to 300 mg KOH/g, a functionality of from 2 to 8, and containing from 5 to 45% of copolymerized oxyethylene, based on the total weight of said polyether polyol 3), wherein said polyether polyols do not contain pure EO terminal blocks;and
4) from 0 to 50%, based on 100% by weight of said polyol blend, of a polyether polyol having a hydroxyl number of from 10 to 45 mg KOH/g and a functionality of from 2 to 8. |
