GB1513807A - High-temperature resistant isocyanurate foams - Google Patents

Abstract

1513807 Isocyanurate foams BASF WYANDOTTE CORP 14 Oct 1975 [24 Dec 1974] 42065/75 Heading C3R An isocyanurate foam is the reaction product of (a) a polyarylpolyalkylene polyisocyanate having a functionality of from 2À2 to 3À5 or an NCO -terminated prepolymer thereof (b) from 5 to 40 p.b.w. of a nitrogen-containing polyether polyol having a hydroxyl number of from 100- 900 and a nitrogen content of from 1-15% wt., (c) from 10-40 p.b.w. of a fluorocarbon blowing agent and (d) from 1-6 p.b.w. of a 1,3,5- tris(N,N - dialkylaminoalkyl) - S - hexahydrotriazine trimerization catalyst or the alkylene oxide and water adducts thereof, said parts being based on 100 p.b.w. of polyisocyanate. Preferred component (a) is a crude polyphenyl polymethylene polyisocyanate mixture having a viscosity of from 150-250 c.p.s. at 25‹ C., an NCO content of at least 31% wt. and having from 42-48% wt. of its NCO content present as a monomeric diphenylmethane diisocyanate; and is prepared by the phosgenation of anilineformaldehyde reaction products. The NCO- terminated prepolymer is prepared by reacting a stoichiometric excess of the polyaryl polyalkylene polyisocyanate with an organic compound having at least 2 reactive hydrogen atoms. Component (b) may be prepared by the reaction of an alkylene oxide with a compound selected from ammonia, alkylene polyamines, polyalkylene polyamines, primary alkylamines, primary aralkylamines and Mannich condensation products of a phenolic compound with formaldehyde and an alkanolamine. Optional ingredients include surfactants, fillers and pigments, and additional catalysts, e.g. catalysts which promote carbodiimide linkages, such as phospholene oxides, methyl alcohol, furfuryl alcohol, 2,4,6 - tris(dialkanolamino) - S - triazine and 2,4 - bis(dialkylamino) - 6 - N- (alkylhydroxyalkylamino) - )S - triazines, and urethane catalysts such as tertiary amines and metallo-organic salts. In the examples polyisocyanurate foams are prepared from the following formulations: (1) polyphenylpolymethylene isocyanate, trichlorofluoromethane, 1,3,5 - tris(dimethylaminopropyl) - hexahydrotriazine (TDH), a silicone surfactant, a polyol (OH number 530) prepared by the reaction of propylene oxide with the Mannich condensation product of HCHO, diethanolamine and a mixture of phenol and cresols, and either (a) bis(diethylamino) - N - methylhydroxyethanolamino - S triazine (DMT) and dibutyltin dilaurate (DBTL), or (b) furfuryl alcohol and either DBTL or dibutyltin diacetate; or (2) polyphenylpolymethylene - isocyanate, trichlorofluoromethane, TDH, DMT, DBTL, a silicone surfactant, and a polyol (OH number 450) prepared by the reaction of ethylene oxide with the propylene oxide adduct of ethylene diamine alone or in admixture with a polyol which is the ethylene oxide adduct of ethylene diamine.