BLOWING AGENTS FOR POLYURETHANE FOAM

摘要

A method for the continuous manufacture of flexible free rise polyurethane foam from reactants comprising at least one polyol and at least one reactive isocyanate where the reaction mixture includes water as a blowing agent and CO2 is incorporated into one of the liquid reactants, or into a blend of one or more of the liquid reactants, and the reactants are introduced under pressure through feed lines into a conventional mixer through two or more feed streams, and the reacting mixture is discharged from the mixer, wherein the improvement comprises injecting gaseous CO2 under pressure into the feed stream of one or more of the liquid reactants of the foam forming composition at a distance from the mixer which will maximize the dissolution of CO2 in the feed stream.