Foams and foamable compositions containing halogenated olefin blowing agents
View Patent ↗The invention provides foam forming methods that comprise: (a) preparing a foamable system comprising at least one hydrohaloolefin; and (b) ensuring either (i) the substantial absence of long-term decomposition-inducing contact between said hydrofluoroolefin and an amine-containing catalyst; (ii) that an effective amount of surfactant is available in the system under conditions which prevent long term exposure of the surfactant to a long-term decomposition reaction environment; or (iii) a combination of (i) and (ii). Related methods, foamable systems and foams are also disclosed. Preferred embodiments provide polyurethane and polyisocyanurate foams and methods for the preparation thereof, including closed-celled, polyurethane and polyisocyanurate foams and methods for their preparation. The preferred foams are characterized by a fine uniform cell structure and little or no foam collapse. The foams are preferably produced with a polyol premix composition which comprises a combination of a hydrohaloolefin blowing agent, a polyol, a silicone surfactant, a catalyst and is further characterized by being substantially free of added water.
1. A foam forming method comprising:
(a) providing a foamable system comprising: (i) polyol contained in a B-side; (ii) isocyanate reactive with said polyol in an A-side; (ii) a catalytically effective amount of an amine-containing catalyst; and (iii) blowing agent comprising trans-1-chloro-3,3,3-trifluoropropene (transHFCO-1233zd) and water, wherein said transHFCO-1233zd is decomposition reactive with said amine-containing catalyst, said providing step comprising forming said B-side to include said trans-1-chloro-3,3,3-trifluoropropene (transHFCO-1233zd) and said amine-containing catalyst, and to be substantially free of water;
(b) storing said B-side for a storage period of at least about 2 months; and
(c) after said storage step (b) forming a foam from the foamable system provided in step (a) by mixing said stored B-side with said A-side.
2. The foam forming method of claim 1 wherein said B side is storage stable for a period of at least about 3 months.
3. The foam forming method of claim 1 wherein said B side is storage stable for a period of at least about 6 months.
4. The foam forming method of claim 1 wherein said B side does not contain a substantial amount of a polar solvent.
5. The foam forming method of claim 1 wherein said B side is substantially free of polar solvents.
6. The foam forming method of claim 1 wherein a gas-generating co-blowing agent other than water is included in said A side, said B side, or both.
7. The foam forming method of claim 6 wherein said gas-generating co-blowing agent comprises formic acid.
8. The foam forming method of claim 1 wherein said B side is storage stable for a period of at least about 2 months.
9. A foam formed from the method of claim 1 .