FOAMS AND FOAMABLE COMPOSITIONS CONTAINING HALOGENATED OLEFIN BLOWING AGENTS
Publication Date: 2014-May-05
The IP.com Prior Art Database
The invention provides foam forming methods that comprise: (a) preparing an A side/ B side type foamable system comprising a polyisocyanate, a polyol, an amine-containing catalyst, at least one hydrohaloolefin, and a surfactant; and (b) ensuring that an effective amount of water is available in the system under conditions which prevent long term exposure of the surfactant to a long-term decomposition reaction environment. 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 surfactant, a catalyst and is further characterized by being substantially free of added water.
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FOAMS AND FOAMABLE COMPOSITIONS CONTAINING
HALOGENATED OLEFIN BLOWING AGENTS
FIELD OF THE INVENTION
The present invention pertains to foams and methods for the preparation thereof, and in
particular to polyurethane and polyisocyanurate foams and methods for the preparation thereof.
BACKGROUND OF THE INVENTION
The class of foams known as rigid to semi-rigid polyurethane or polyisocyanurate foams has 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 foam for cushioning and safety application such as steering wheels and other automotive or aerospace cabin parts, shoe soles, and amusement park restraints. An important factor in the large-scale commercial success of many rigid to semi-rigid polyurethane foams has been the ability of such foams to provide a
good balance of properties. In general, rigid polyurethane and polyisocyanurate foams are known to provide outstanding thermal insulation, excellent fire resistance properties, and superior structural properties at reasonably low densities. Integral skin foams are known to produce a tough durable outer skin and a cellular, cushioning core.
As is known, blowing agents are used to form the cellular structure required for such
foams. It has been common to use liquid fluorocarbon blowing agents because of their ease of use and ability to produce foams with superior mechanical and thermal insulation properties. Fluorocarbons not only act as blowing agents by virtue of their volatility, but also are
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encapsulated or entrained in the closed cell structure of the rigid foam and are generally the major contributor to the low thermal conductivity properties of the rigid urethane foams. The use of fluorocarbon as the preferred commercial expansion or blowing agent in insulating foam applications is based in part on the resulting k-factor associated with the foam produced. The k- factor provides a measure of the ability of the foam to resist the transfer of heat through the foam
material. As the k-factor decreases, this is an indication that the material is more resistant to heat transfer and therefore a better foam for insulation purposes. Thus, materials that produce lower k-factor foams are desirable and advantageous.
It is known in the art to producerigid or semi-rigid polyurethane and polyisocyanurate foams by reacting one or more polyisocyanate(s) with one or more polyol(s) in the presence of
one or more blowing agent(s) one or more catalyst(s) and one or more surfactant(s). Water is commonly used as a blowing agent in such systems. Other blowing agents which have been used include hydrocarbons, fluorocarbons, chlorocarbons, chlorofluorocarbons, hydrochlorofluorocarbons, halogenated hydrocarbons, ethers, esters, aldehydes, alcohols,...