Polyol compositions, a process for the production of these polyol compositions, and their use in the production of open celled polyurethane foams having high airflow

A process for the production of an open celled, flexible polyurethane foam comprising

• (I) preparing an isocyanate-reactive component comprising (a) an in-situ formed polyol blend having an overall hydroxyl number of from about 56 to about 250, and an average functionality greater than 2, and preparing said in-situ formed polyol blend by
• A) introducing into a reaction vessel a mixture comprising:
• (1) an initial starter (Si) comprising one or more monofunctional compounds having a hydroxyl number of less than about 56 and containing less than 20% by weight of copolymerized oxyethylene, based on 100% by weight of said one or more monofunctional compounds,
• and
• (2) a double metal cyanide (DMc) catalyst,
• B) feeding
• (1) an epoxide component comprising propylene oxide and ethylene oxide in a weight ratio of from 100:0 to 20:80,
• into the reaction vessel;
• C) allowing said epoxide component and the initial starter (Si) to react and continue to polymerize by feeding said epoxide component until the equivalent weight of said one or more monofunctional compound is increased by at least 10% by weight and reaches a value between about 1,500 and about 6,000;
• D) continuously adding
• (1) one or more low molecular weight starters (Sc) having a functionality of greater than 2 to about 6 and an equivalent weight of about 28 to about 400
• into the reaction vessel while continuing to feed said epoxide component;
• E) completing addition of the continuous starter (Sc);
• and
• F) allowing the mixture to continue to polymerize in the reaction vessel until said in-situ formed polyol blend has an overall hydroxyl number of from about 56 to about 250, an average functionality of greater than 2, and comprises
• (1) one or more polyether monols having a hydroxyl number of less than 56, and containing less than 20% by weight of copolymerized oxyethylene, based on 100% by weight of F)(1);
• and
• (2) one or more polyether polyols having a hydroxyl number of about 47 to about 300, an average functionality of greater than 2 to about 6, and containing from about 5 to about 45% by weight of copolymerized oxyethylene, based on 100% by weight of F)(2);
• wherein F)(1) and F)(2) are each present in the in-situ formed polyol blend in an amount of from about 25 to 75% by weight, with the combined weight of F)(1) and F)(2) totaling 100% by weight of said in-situ formed polyol blend;
• (II) forming a polyol composition by blending or mixing (a) said in-situ formed polyol blend, with
• (b) one or more polyether polyols having a functionality of 2 to 8, a hydroxyl number of 20 to 240 and comprising at least 50% of copolymerized oxyethylene, based on 100% by weight of component (b);
• wherein (a) said in-situ formed polyol blend is provided in an amount of from 20 to 98% by weight, and (b) said one or more polyether polyols is provided in an amount of from 2 to 80% by weight;
• (III) reacting an isocyanate-functional component with said polyol composition which comprises (a) said in-situ formed polyol blend, in the presence of a blowing agent, a catalyst, and a surfactant, wherein the isocyanate-functional component and the polyol composition are reacted at an isocyanate index of 85 to 120.