| 摘要 |
Foamed products are obtained by heating a mixture of a polyester, a polyisocyanate, a catalyst generator for generating a catalyst for the polyester-polyisocyanate reaction and a water generator. Water generators specified are inorganic salts containing water of crystallization, particularly carbonates, e.g. sodium carbonate decahydrate. Catalyst generators specified are tertiary amine salts, particularly the hydrochlorides of N-methyl, N-ethyl and N-phenyl morpholine and a mixture of aniline and b ,b 1-dichlorodiethylether which generates N-phenyl morpholine by cyclisation and evolution of hydrogen chloride. With carbonates as water generators any evolved hydrogen chloride from the catalyst generator is neutralized while causing evolution of carbon dioxide which assists foam production. Linear polyesters may be used to produce elastic foams and branched polyesters for rigid foams. The mixes before heating are relatively stable and may be kept for long periods at 60 DEG F. without premature reaction. A dispersing agent may be included. In examples foams are produced from typical mixes using an adipic acid-glycol polyester, of acid number 1.5 and hydroxyl number 60, 2.4 tolylene diisocyanate, sodium carbonate decahydrate, N-ethyl morpholine hydrochloride or a mixture of aniline and dichlorodiethyl ether and as dispersing agent a condensation product of ethylene oxide and stearic acid. The mix is placed in a mould, which may be preheated, and heated to about 250 DEG F. for 30 minutes to bring about reaction and foaming. |
