Water-blown methylene di:isocyanate based flexible polyurethane foam - has specific density and compression hardness obtd. by reacting methylene di:phenyl isocyanate with active hydrogen cpd. e.g. polyether

摘要

Mfr. of flexible PU foam is by reaction of an MDI cpd. (I) with an active-H cpd. (II) of functionality 2-4 and equiv. wt. 750-5000, 0-5 pts. wt. water per 100 pts. (II) and opt. conventional additives including blowing agents, NCO index is 10-60. Mfr. is pref. water-blown and halocarbon free, with a wt. ratio of (II) to water of 20 to 200. (II) is a polyester or polyester polyol or polyether polyamine. (I) may be MDI, MDI prepolymer, crude MDI opt. with some NCO gps. converted to carbodiimide, isocyanaurate etc. NCO functionality is pref. 1.9-2.9, esp. 2-2.5. Functionality of (II) is pref. 2-3, equiv. wt. pref. 1000-2500.