Oxidn resistant flexible polyurethane foam - by reacting normal components in presence of organo tin cpd as gelling catalyst

摘要

Flexible cellular polyurethane is prepd. by reacting (1) a polyol contg. >=2 active H atoms per mol. as determined by the Zerewitinoff method, with (2) a stoichiometrical excess of a polyisocyanate, in the presence of (3) a blowing agent, and (4) of a gelling catalyst of formula: R'aSnX4-a, (R'3Sn)2S, (R3'SN)-2-(OC(O) C(O)O)-, R'2SnS, (R'Sn-(OC(O)CH=CHC(O)O)-or (R'3Sn)2-(OC(O)CH=CHC(O)O)- (where R' is methyl, allyl, benzyl, (substd.)phenyl, or benzyl, X is Cl, Br, -S-CO-NR22. -SR3, -SCnH2nC(O)OR3, or -OC(O)R4, R2 and R3 are each 1-20C alkyl, cycloalkyl, phenylalkyl, alkylphenyl, or phenyl, R4 is 1-20C alkyl, cycloalkyl, or (substd) phenyl, a is 1,2 or 3, and n is 1-12). The process gives cellular polyurethanes with a better resistance to oxidn. and heat, the flexible cellular structure maintaining its integrity and resilience for long periods. The cpds. have practically no effect on the foaming process, or the physical properties, esp. resilience of the foams.