VISCOELASTIC FOAMS HAVING HIGH AIR FLOW

摘要

A viscoelastic polyurethane foam is the reaction product of at least one natural oil derived polyol and at least one aromatic compound having an aver age of more than one isocyanate group. A viscoelastic polyurethane foam has an air flow of at least about 0.5 l/s, wherein the foam is formed in the sub stantial absence of copolymer polyol and has not (yet) been mechanically ret iculated and is preferably prepared using at least one natural oil derived p olyol, more preferably in an amount of at least about 20 weight percent of t he polyols used. A process of preparing a viscoelastic foam, comprises steps of (A) forming a reaction mixture including at least one polyol, at least o ne polyisocyanate, water, at least one catalyst wherein a the polyol compris es at least one natural oil derived polyol; and (B) subjecting the reaction mixture to conditions sufficient to result in the reaction mixture to expand and cure to form a viscoelastic polyurethane foam. In another embodiment, a process comprises steps of (a) forming a natural oil derived polyol composi tion comprising at least one natural oil derived polyol and water; (b) admix ing at least one gelling catalyst and at least one blowing catalyst with the natural oil derived polyol composition to form a catalyst polyol admixture; (c) supplying an isocyanate in an amount corresponding to an isocyanate ind ex for a pMDI of at least about 65 and at most about 95 or, when the isocyan ate is a TDI or MDI or combination thereof, at least about 80 and at most ab out 105; and (c) admixing the isocyanate with the catalyst polyol admixture.