| 摘要 |
The invention provides polyurethane and polyisocyanurate foams and methods for the preparation thereof More particularly, the invention relates to open-celled, polyurethane and polyisocyanurate foams and methods for their preparation. The foams are characterized by a fine uniform cell structure and little or no foam collapse. The foams are produced with a polyol premix composition which comprises a combination of a hydrohaloolefin blowing agent, a polyol, a silicone surfactant, and a catalyst which is an adduct of an amine and an organic acid. |
| 主权项 |
1. A polyol premix composition that has been aged which comprises a combination of: (a) from about 1 wt % to about 30 wt % of a blowing agent, (b) from about 60 wt. % to about 95 wt. % of a polyol, (c) from about 0.5 wt. % to about 5.0 wt. % of a silicone surfactant, and (d) from about 0.2 wt. % to about 8.0 wt. % of a catalyst which catalyst is an adduct of a tertiary amine and an organic acid comprising acetic acid or formic acid, wherein the blowing agent comprises: (i) from about 10 wt % to about 70 wt % of a hydrohaloolefin based on the weight of the blowing agent, wherein said hydrohaloolefin is selected from the group consisting of trans-1,3,3,3-tetrafluoropropene, trans-1-chloro-3,3,3-trifluoropropene, and combinations thereof, and (ii) an auxiliary blowing agent selected from the group consisting of hydrocarbon, fluorocarbon, chlorocarbon, fluorochlorocarbon, halogenated hydrocarbon, ethers, esters, aldehydes, ketones, halogenated ethers, CO2 generating material, or combinations thereof, wherein the catalyst and the hydrohaloolefin blowing agent exhibit sufficiently reduced reactivity with each other, as compared to a composition comprising the blowing agent and catalyst that is not an adduct of an amine and an organic acid, such that foam formed from the polyol premix composition exhibits substantially no cell collapse after said premix has been aged at 120° F. for 62 hours. |
