Catalysts For Polyurethane Foam Polyol Premixes Containing Halogenated Olefin Blowing Agents

Abstract

The invention provides polyurethane and polyisocyanurate foams and methods for the preparation thereof. More particularly, the invention relates to closed-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 non-amine catalyst used alone or in combination with an amine catalyst.

Description

CROSS REFERENCE TO RELATED APPLICATIONS[0001]This application is related to and claims the priority benefit of United States provisional application Ser. No. 61 / 287,603 filed Dec. 17, 2009, the contents of which are incorporated herein by reference.FIELD OF THE INVENTION[0002]The present invention pertains to polyurethane and polyisocyanurate foams and methods for the preparation thereof.BACKGROUND OF THE INVENTION[0003]Low density, rigid to semi-rigid polyurethane or polyisocyanurate foams have utility in a wide variety of insulation applications including roofing systems, building panels, building envelope insulation, spray applied foams, one and two component froth foams, insulation for refrigerators and freezers, and so called integral skin for application such as steering wheels and other automotive or aerospace cabin parts, shoe soles, and amusement park restraints. Critical to the large-scale commercial acceptance of rigid polyurethane foams is their ability to provide a good...

AI Technical Summary

Benefits of technology

[0010]While it is possible to solve the problem by separating the blowing agent, surfactant, and catalyst, for example by adding the blowing agent, amine catalyst, or surfactant to the polyisocyanate, (“A” component) or by introducing the blowing agent, amine catalyst, or surfactant using a separate stream from the “A” or “B” component, a preferred solution is one that does not require a change in the way the foams are made. It has now been found that non-amine catalysts, e.g. inorgano-metallic catalysts, organo-metallic catalysts and / or quaternary ammonium carboxylate catalysts, either alone or in combination with amine catalysts, can extend the shelf life of polyol premixes containing hydrohaloolefins, such as, but not limited to 1234ze(E), 1233zd(E), and / or 1336mzzm(Z), such that good quality foams can be produced even if the polyol blend has been aged several weeks or months.

Problems solved by technology

It has been found that, subsequent to the decomposition of the blowing agent, the molecular weight of the polymeric silicone surfactants, if present, is detrimentally altered.