GB1279894A - Rigid fire-retardant polyurethane foams and preparation thereof - Google Patents

Abstract

1279894 Rigid polyurethane foams JEFFERSON CHEMICAL CO Inc 14 July 1970 [22 July 1969] 34215/70 Headings C3C and C3R Rigid fire-retardant polyurethane foams having more than 90% closed cells and a K factor less than 0À13 are prepared by reacting in the presence of a catalyst of urethane formation, a blowing agent and a surfactant, (a) an isocyanate-terminated prepolymer which is the reaction product of an excess of a polymethylene polyphenylisocyanate having a functionality greater than two and a reactive phosphoruscontaining compound containing more than one reactive hydrogen atom and (b) a sucrose polyol which is the reaction product of 7 to 14 mols. of propylene oxide, butylene oxide or a mixture of propylene oxide or butylene oxide with ethylene oxide, per mol. of sucrose. The preferred phosphorus-containing compounds are polyols produced by the reaction of alkaline oxides having 2 to 4 carbon atoms with phosphorus acids and esters thereof having reactive OH groups. The sucrose polyol may be used in a blend with a glycerol/propylene oxide adduct and a sorbitol/propylene oxide adduct. In a typical example, a prepolymer was formed from a polymethylene polyphenyl isocyanate having functionality of 2À6 and a commercial phosphorus containing diol and was added to a mixture of a sucrose 9À5 mol. propylene oxide adduct, a silicone surfactant, dimethylaminoethanol, tetramethylpropane diamine and a fluorocarbon blowing agent to form a rigid foam.