low density polyurethane elastomer foam with high ball shoulder

摘要

the present disclosure provides a polyurethane elastomer foam formed by reacting a mixture that includes 60 to 50 weight percent (% by weight) of a polyol formulation and 40 to 50 weight% prepolymer isocyanate (% weight based on the total weight of the mixture). the polyol formulation includes 85 to 92% by weight of a polytetramethylene ether (ptmeg) with a weighted molecular weight of 1,900 to 2,100 and a hydroxyl number of about 53 to about 60; 4 to 10% by weight of monoethylene glycol; an insufflation agent; a catalyst; and a surfactant (values in% by weight for the polyol formulation based on the total weight of the polyol formulation). the isocyanate prepolymer includes 55 to 70% by weight of an isocyanate blend that has at least 90% by weight of 4,4'-diphenylmethane diisocyanate; and from 30 to 45% by weight of ptmeg, where the isocyanate prepolymer has an isocyanate content of 16 to 21% by weight based on the total weight of the isocyanate prepolymer, and the polyurethane elastomer foam has a ball shoulder of at least 50%, measured according to astm d3574 on a 10 mm thick test plate.