Abstract Flexible foam with a soft skin is made by a one-shot process involving overpacking a mold with a mixture, in critical proportions, of: (a) a methylenebis(phenyl isocyanate) having a functionality between 2 and 2.7; (b) an hydroxyl terminated polyoxypropylene ether triol immiscible with (a); (c) an hydroxy terminated polyester miscible with (a) but immiscible with (b); (d) a low molecular weight glycol; (e) a volatile liquid blowing agent; and (f) a catalyst. During the mixing, an emulsion is formed thus preventing separation of the ingredients (foam defects). Due to its discontinuity the emulsion gives controlled rupture of cell walls (open cell foam). No surface active agent is used to control cell structure.
A method as in claim 1 in which (a) is a storage stable liquid at temperatures above 15* C obtained by heating a methylenebis (phenyl isocyanate) which is normally solid at 15* C with from 0.1 percent to 3 percent by weight of a trialkyl phosphate at a temperature within the range of 160* C to 250* C until the isocyanate equivalent is within the range of 130 to 150.
Claim 2
Dependent Claim
14 words
A method as in claim 1 in which (b) is polyoxypropylene ether of glycerol.
Claim 3
Dependent Claim
13 words
A method as in claim 1 in which (c) is poly(diethylene glycol adipate).
Claim 4
Dependent Claim
11 words
A method as in claim 1 in which (d) is 1,4-butanediol.
Claim 5
Dependent Claim
12 words
A method as in claim 1 in which (d) is ethylene glycol.
Claim 6
Dependent Claim
14 words
A method as in claim 1 in which the said catalyst is dibutyltin dilaurate.
Claim 7
Dependent Claim
13 words
A method as in claim 1 in which the saId catalyst is triethylenediamine.
Claim 8
Dependent Claim
39 words
A method as in claim 1 in which the said catalyst is selected from the group consisting of triethylenediamine and dibutyltin dilaurate and the said blowing agent is selected from the group consisting of trichloromonofluoromethane, methylene dichloride and trichlorotrifluoroethane.