Stability of polyurethane polyol blends containing halogenated olefin blowing agent

Abstract

A polyol pre-mix composition includes a blowing agent having a halogenated hydroolefin, a polyol, a catalyst composition, and an antioxidant. The antioxidant may be, for example, a benzene diol or a benzene triol or other polyhydroxy-substituted aromatic compound, which is optionally substituted with one or more substituents such as alkyl groups. A two-part system for producing a thermosetting foam blend includes (a) a polyisocyanate and, optionally, one or more isocyanate compatible raw materials; and (b) the polyol pre-mix composition. A method for producing a thermosetting foam blend includes combining: (a) a polyisocyanate; and (b) the polyol pre-mix composition.

Description

[0001]This application is a divisional of U.S. application Ser. No. 14 / 430,289 filed Mar. 23, 2015, which is the United States national phase under 35 USC § 371 of and claims priority to international Application serial number PCT / US2013 / 060510 filed Sep. 19, 2013 which designated the United States of America and claimed priority to U.S. Provisional Patent Application Ser. No. 61 / 704,626 filed Sep. 24, 2012, all of which are incorporated herein by references.FIELD OF THE INVENTION[0002]The present invention relates to a method for stabilizing thermosetting foam blends that include halogenated olefinic blowing agent, such as hydrochlorofluoroolefin (HCFO) HCFO-1233zd. More particularly, the present invention relates to a method for stabilizing thermosetting foam blends using a polyol pre-mix composition which includes one or more antioxidants. The present invention further relates to the stable pre-blend formulations and resulting polyurethane or polyisocyanurate foams.BACKGROUND OF ...

AI Technical Summary

Benefits of technology

The patent text describes the use of antioxidants to stabilize polyol pre-mix compositions containing catalysts and blowing agents. By adding antioxidants to the mix, the shelf life of the composition is increased and the foam produced when combined with a polyisocyanate has better characteristics. The use of antioxidants also prevents the formation of harmful intermediates and makes the foam more environmentally-friendly. The mixture of polyisocyanate and polyol pre-mix composition can be used to create foam with uniform cell structure and low ozone depletion potential. Overall, the use of antioxidants improves the stability and quality of polyol pre-mix compositions.

Problems solved by technology

Currently used blowing agents for thermoset foams include HFC-134a, HFC-245fa, HFC-365mfc, which have relatively high global warming potential, and hydrocarbons such as pentane isomers, which are flammable and have low energy efficiency.

Two-component systems, however, have been found to have reduced shelf-life of the B-side composition, especially those systems which use certain hydrohaloolefins, such as, for example, HFO-1234ze and HCFO-1233zd.

However, if the polyol pre-mix composition is aged prior to treatment with the polyisocyanate, the foams are of lower quality and may even collapse during the formation of the foam.

The poor foam structure is attributed to the reaction of certain catalysts with certain hydrohaloolefins, including HFO-1234ze and HCFO-1233zd, which results in the partial decomposition of the blowing agent and, subsequently, the undesirable modification of the polymeric silicone surfactants.

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