Patent Application
20180312651
The present invention pertains to blowing agents, to foams, to articles made from foams and to methods for the preparation thereof, and in particular to polyurethane and polyisocyanurate foams and methods for the preparation and uses thereof.
The class of foams known as low density, 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. Such foams are also used as so called integral skin foam for cushioning and safety application such as steering wheels and other automotive or aerospace cabin parts, shoe soles, amusement park restraints, and the like. 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, including performance, environmental and safety properties. In general, rigid polyurethane and polyisocyanurate foams should provide outstanding thermal insulation, excellent fire resistance properties, and superior structural properties at reasonably low densities.
As is known, blowing agents are used to form the cellular structure required for such foams. It has been common to use certain liquid fluorocarbon blowing agents because of their ease of use, among other factors. Certain fluorocarbons are capable of not only acting as blowing agents by virtue of their volatility, but also are encapsulated or entrained in the closed cell structure of the foam and are generally the major contributor to the thermal conductivity properties of the rigid urethane foams. After the foam is formed, the k-factor associated with the foam produced 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 generally desirable and advantageous.
In recent years, concern over climate change has driven the development of a new generation of fluorocarbon compounds, which meet the requirements of both ozone depletion and climate change regulations. Two such fluorocarbons are trans-1,3,3,3-tetrafluoropropene (1234ze(E)) and trans-1-chloro-3,3,3-trifluoropropene (1233zd(E)). Honeywell International sells products under the registered trademark SOLSTICE®, including under the trade designation SOLSTICE® GBA containing trans-1,3,3,3-tetrafluoropropene (1234ze(E)) and under the trade designation SOLSTICE® LBA containing trans-1-chloro-3,3,3-trifluoropropene.
In certain non-limiting aspects, the present invention relates to a thermal insulating foam including a thermoset polymer having a plurality of closed cells and a gaseous composition contained in a plurality of said closed cells, said gaseous composition including from about 50 mole % to less than about 100 mole % trans-1-chloro-3,3,3-trifluoropropene and from greater than about 0 mole % to about 50 mole % of methyl formate. Applicants have found that certain important advantages can be unexpectedly achieved by the selection of methyl formate as a co-blowing agent within carefully selected concentration ranges. Among these advantages are reduced cost of the blowing agent composition while unexpectedly maintaining, or in some cases unexpectedly improving one or more of the performance properties of the blowing agent/foam, including thermal conductivity, foam stability, and/or stability. In preferred embodiments these unexpected advantages are achieved for blowing agents that comprise from about 50 mole % to less than about 95 mole % trans-1-chloro-3,3,3-trifluoropropene and from greater than about 5 mole % to about 50 mole % of methyl formate, even more preferably in certain embodiments such advantages are achieved for blowing agents that comprise from about 50 mole % to less than about 75 mole % trans-1-chloro-3,3,3-trifluoropropene and from greater than about 25 mole % to about 50 mole % of methyl formate, and in even more preferred embodiments for blowing agents that comprise from about 50 mole % to about 70 mole % trans-1-chloro-3,3,3-trifluoropropene and from about 30 mole % to about 50 mole % of methyl formate.
Unless otherwise specifically indicated herein, the mole percentages for % trans-1-chloro-3,3,3-trifluoropropene and methyl formate are based on the total of said trans-1-chloro-3,3,3-trifluoropropene and methyl formate. The thermal insulating foam, in certain preferred aspects, has a K-value after 28 days of aging at 55° F. of not greater than about 0.14; a K-value after 28 days of aging at 40° F. of not greater than about 0.13; and/or a K-value after 28 days of aging at 20° F. of not greater than about 0.13. In certain preferred aspects of the present invention, methyl formate is present in an amount of from greater than about 25 mole % to about 50 mole % or in certain embodiments from about 30 mole % to about 50 mole %
The present invention also relates to a pour-in-place foam panel that includes a foam composition according to the present invention. In certain preferred aspects, the gaseous composition contained in a plurality of the cells in said foam includes methyl formate in an amount of from greater than about 5 mole % to about 50 mole % and from about 50 mole % to less than about 95 mole % trans-1-chloro-3,3,3-trifluoropropene, in certain embodiments more preferably from greater than about 25 mole % to about 50 mole % methyl formate and from about 50 mole % to less than about 75 mole % trans-1-chloro-3,3,3-trifluoropropene, and in even further embodiments from about 30 mole % to about 50 mole % methyl formate and from about 50 mole % to about 70 mole % trans-1-chloro-3,3,3-trifluoropropene.
The present invention also relates to a thermal insulating article comprising any of the foams provided herein.
In even further aspects, the present invention relates to a polyol premix for forming an polyurethane or polyisocyanurate pour-in-place foam panel including a blowing agent composition according to the present invention. In certain of such embodiments, the premix composition comprises a blowing agent that comprises from about 50 mole % to less than about 100 mole % trans-1-chloro-3,3,3-trifluoropropene and greater than about 0 mole % to about 50 mole % of methyl formate, even more preferably from about 50 mole % to less than about 95 mole % trans-1-chloro-3,3,3-trifluoropropene and greater than about 5 mole % to about 50 mole % of methyl formate, even more preferably from about 50 mole % to less than about 75 mole % trans-1-chloro-3,3,3-trifluoropropene and from greater than about 25 mole % to about 50 mole % of methyl formate, and even more preferably from about 50 mole % to about 70 mole % trans-1-chloro-3,3,3-trifluoropropene and from about 30 mole % to about 50 mole % of methyl formate. The polyol component may be present in preferred embodiments an amount of from about 60 wt. % to about 95 wt. % of the premix and the blowing agent composition in accordance with the present invention is present in the premix in an amount of from about 1 wt. % to about 30 wt. %.
The blowing agent composition may also include one or more additional blowing agents other than trans-1-chloro-3,3,3-trifluoropropene or methyl formate. Such additional blowing agents may be selected from water, organic acids that produce CO2 and/or CO, hydrocarbons; ethers, halogenated ethers; esters, alcohols, aldehydes, ketones, pentafluorobutane; pentafluoropropane; hexafluoropropane; heptafluoropropane; trans-1,2 dichloroethylene; methylal, 1-chloro-1,2,2,2-tetrafluoroethane (HCFC-124); 1,1-dichloro-1-fluoroethane (HCFC-141b); 1,1,1,2-tetrafluoroethane (HFC-134a); 1,1,2,2-tetrafluoroethane (HFC-134); 1-chloro 1,1-difluoroethane (HCFC-142b); 1,1,1,3,3-pentafluorobutane (HFC-365mfc); 1,1,1,2,3,3,3-heptafluoropropane (HFC-227ea); trichlorofluoromethane (CFC-11); dichlorodifluoromethane (CFC-12); dichlorofluoromethane (HCFC-22); 1,1,1,3,3,3-hexafluoropropane (HFC-236fa); 1,1,1,2,3,3-hexafluoropropane (HFC-236e); 1,1,1,2,3,3,3-heptafluoropropane (HFC-227ea), difluoromethane (HFC-32); 1,1-difluoroethane (HFC-152a); 1,1,1,3,3-pentafluoropropane (HFC-245fa); 1,3,3,3-tetrafluoropropene (HFO-1234ze); 1,1,1,4,4,4-hexafluorobut-2-ene (HFO-1336mzzm); butane; isobutane; n-pentane, iso-pentane, cyclopentane and combinations thereof.
Additional agents for use in the premix may include, but are not limited to, a silicone surfactant, a non-silicone surfactant, a metal catalyst, an amine catalyst, a flame retardant, and combinations thereof.
The foregoing embodiments are not necessarily limiting to the invention. To this end, the present invention includes additional and all alternative embodiments provided below, including those expressly discussed and those apparent to the skilled artisan on the basis of the disclosure and/or data provided.
The present compositions can generally be in the form of blowing agent compositions, foamable compositions, or the resulting foams. In each case, the present invention requires at least one fluoroalkene compound as described herein and optionally but preferably one or more additional components, as described in more detail below.
In certain embodiments, the present invention is directed to blowing agent compositions which may comprise, in addition to either 1234ze(E) or 1233zd(E) at least one additional fluoroalkene containing from 2 to 6, preferably 3 to 5 carbon atoms, more preferably 3 to 4 carbon atoms, and in certain embodiments most preferably three carbon atoms, and at least one carbon-carbon double bond. The fluoroalkene compounds of the present invention are sometimes referred to herein for the purpose of convenience as hydrofluoro-olefins or “HFOs” if they contain at least one hydrogen. Although it is contemplated that the HFOs of the present invention may contain two carbon-carbon double bonds, such compounds at the present time are not considered to be preferred. For HFOs which also contain at least one chlorine atom, the designation HFCO is sometimes used herein
In further aspects, the HFO or HFCO compounds comprise one or more compounds in accordance with Formula I below:
where each R is independently Cl, F, Br, I or H
R′ is (CR2)nY,
Y is CRF2
and n is 0, 1, 2 or 3, preferably 0 or 1, it being generally preferred however that either Br is not present in the compound or when Br is present in the compound there is no hydrogen in the compound.
In highly preferred embodiments, Y is CF3, n is 0 or 1 (most preferably 0) and at least one of the remaining Rs is F or Cl, and preferably no R is Br, or when Br is present there is no hydrogen in the compound. It is preferred in certain cases that no R in Formula I is Br.
Applicants believe that, in general, the compounds of the above identified Formula I are generally effective and exhibit utility in blowing agent compositions in accordance with the teachings contained herein. However, applicants have surprisingly and unexpectedly found that certain of the compounds having a structure in accordance with the formula described above, as discussed in greater detail below, exhibit a highly desirable low level of toxicity compared to other of such compounds. In further aspects, certain of the compounds of Formula I have highly desirable physical properties and/or thermal conductivity/insulation under a wide array of conditions, as compared to other of such compounds and/or existing blowing agents.
In certain preferred embodiments, the compound of the present invention comprises a C3 or C4 HFCO or HFO, preferably a C3 HFCO or HFO, and more preferably a compound in accordance with Formula I in which Y is CF3, n is 0, at least one R on the unsaturated terminal carbon is H, and at least one of the remaining Rs is F or Cl. HFCO-1233 is one example of such a preferred HCFO compound, and tetrafluoropropenes, particularly HFO-1234, is one example of such a preferred HFO compound.
The term “HFCO-1233” is used herein to refer to all trifluoromonochloropropenes. Among the trifluoromonochloropropenes are included both cis- and trans-1,1,1-trifluo-3,chlororopropene (HFCO-1233zd or 1233zd). The term “HFCO-1233zd” or “1233zd” is used herein generically to refer to 1,1,1-trifluo-3,chloro-propene, independent of whether it is the cis- or trans-form. The terms “cis HFCO-1233zd” and “transHFCO-1233zd” are used herein to describe the cis- and trans-forms of 1,1,1-trifluo,3-chlororopropene, respectively. The term “HFCO-1233zd” therefore includes within its scope cis HFCO-1233zd (also referred to as 1233zd(Z)), transHFCO-1233zd (also referred to as 1233(E)), and all combinations and mixtures of these.
The term “HFO-1234” includes HFO-1234yf, (cis)HFO-1234ze and (trans)HFO-1234ze, with HFO-1234ze being generally preferred and trans HFO-1234ze being highly preferred in certain embodiments. Although the properties of (cis)HFO-1234ze and (trans)HFO-1234ze differ in at least some respects, it is contemplated that each of these compounds is adaptable for use, either alone or together with other compounds including its stereo isomer, in connection with each of the applications, methods and systems described herein. For example, (trans)HFO-1234ze may be preferred for use in certain systems because of its relatively low boiling point (−19° C.), while (cis)HFO-1234ze, with a boiling point of +9° C., may be preferred in other applications. Of course, it is likely that combinations of the cis- and trans-isomers will be acceptable and/or preferred in many embodiments. Accordingly, it is to be understood that the terms “HFO-1234ze” and 1,3,3,3-tetrafluoropropene refer to both stereo isomers, and the use of this term is intended to indicate that each of the cis- and trans-forms applies and/or is useful for the stated purpose unless otherwise indicated.
In certain preferred forms, compositions of the present invention have a Global Warming Potential (GWP) of not greater than about 1000, more preferably not greater than about 500, and even more preferably not greater than about 150. In certain embodiments, the GWP of the present compositions is not greater than about 100 and even more preferably not greater than about 75. As used herein, “GWP” is measured relative to that of carbon dioxide and over a 100 year time horizon, as defined in “The Scientific Assessment of Ozone Depletion, 2002, a report of the World Meteorological Association's Global Ozone Research and Monitoring Project,” which is incorporated herein by reference.
In certain preferred forms, the present compositions also preferably have an Ozone Depletion Potential (ODP) of not greater than 0.05, more preferably not greater than 0.02 and even more preferably about zero. As used herein, “ODP” is as defined in “The Scientific Assessment of Ozone Depletion, 2002, A report of the World Meteorological Association's Global Ozone Research and Monitoring Project,” which is incorporated herein by reference.
In certain particular, but non-limiting aspects of the present invention, Applicants have come to recognize the existence of unexpected and surprising advantages when 1233zd (preferably the trans form thereof, 1233zd(E)) or 1234ze (preferably the trans form thereof, 1234ze(E)) are combined with methyl formate as described here is used as a blowing agent/contained gas in thermally insulative foams, panel foam and/or pour-in-place panel foam applications. One particular advantage provided herein is that the foams and articles formed therefrom have the equivalent or superior physical qualities to existing foams, but provide a much lower GWP. Another advantage is that such foams maintain, and in some embodiments demonstrate improved properties, including thermal properties (e.g. conductivity and insulation) over a wide array of environmental conditions (e.g. temperature and humidity), as compared to foams formed with existing blowing agents, and that those properties are surprisingly maintained as the foam is aged and in that such advantages can be unexpectedly achieved while providing a highly advantageous advantage in the cost of the blowing agent.
As is known by those skilled in the art, polyurethane foam is used extensively as the core insulation material in several types of articles. Previously, some of the most commonly used blowing agents for polyurethane foams included HFC-245fa, HFC-134a and hydrocarbons. Such compounds are commonly used in the majority of the polyurethane foam markets in developing countries. As the low global warming potential initiative emerges in developed countries and the HCFC phase-out in developing countries approaches, there is an increasing worldwide need and desire for low global warming potential (LGWP) blowing agents.
Applicants illustrate herein that one advantage of the present invention is that the resulting foam product including the blowing agent of the present invention, alone or in combination with one or more commonly used other co-blowing agents, has improved characteristics of the foam, and surprisingly, resulted in improved flammability and thermal conductivity across a wide array of temperature conditions and as the foam ages. As demonstrated in the data herein, in thermally insulating panel foams, or pour-in-place foam panels, the 1233zd/1234ze methyl formate blowing agents of the present invention in preferred embodiments are capable of achieving comparable physical properties (e.g. free rise density, core density, etc.) to foams formed with existing blowing agents, which makes them suitable drop-in replacements within existing foam formulations. Foams formed in accordance preferred aspects of the present invention are also demonstrated herein to surprisingly and unexpectedly excellent thermal insulation properties, initially and after 3 months of aging, than foams formed with 245fa, C5 hydrocarbons, or methyl formate alone. They are also surprisingly demonstrated to have superior flammability properties than methyl formate alone and 141b. Accordingly, foams formed in accordance with the present invention exhibit a myriad of improved properties over foams formed with several existing blowing agents.
More particularly, the preferred blowing agent of the present invention has been surprisingly found to result in improved flammability and thermal stability, initially and particularly after foam aging, as compared to foams produced using methyl formate alone. Moreover, 1233zd blended with 50 mol % or less of methyl formate, in certain embodiments from greater than about 25 mol % to about 50 mol % methyl formate, and in further embodiments from about 30 mol % to about 50 mol % methyl formate, surprisingly and unexpectedly exhibited similar thermal conductivity to 1233zd, alone, and/or a K-value of less than 0.14 when measured at temperatures below 55° F. and a K-value of less than 0.13 when measured at temperatures below 40° F. or 20° F. This makes it favorable for use in a wide-array of cold storage applications, such as coolers and freezer, and unexpectedly provided that the ability to achieve the advantageous thermal conductivity and/or other properties at a highly advantageous and substantially lower cost to foam production. Examples of cold storage applications for use with such blending blowing agents include, but are not limited to, walk-in coolers and freezers, commercial refrigeration, industrial coolers and freezers, iso-containers or any container used for transporting cold materials, or any similar application where it is desirable to cool or maintain the temperature of an article below room temperature.
1233zd/methyl formate blends in accordance with the present invention have also been found to unexpectedly impart superior physical properties to the resulting foams. In foams aged under stringent conditions (e.g. at temperatures at or above 90° F. and at or above 70° F./95% relative humidity), 1233zd/methyl formate blends were found to maintain similar dimensional stability as foams using 1233zd alone. This is particularly true in embodiments where methyl formate is provided in an amount less than about 75 mol % and in certain embodiments wherein methyl formate is provided in an amount at or below 50 mol %.
Accordingly, the present invention relates to the use of 1233zd or 1234ze, but in certain preferred aspects to HCFO-1233zd(E), as a blowing agent in polyol premix and in foams, particularly in premixes and foams useful as a panel foam. In addition to the foregoing, a nonexclusive list of other co-blowing agents which may be added according to the needs of a particular application include, but are not limited to, water, organic acids that produce CO2 and/or CO, hydrocarbons; ethers, halogenated ethers; esters, alcohols, aldehydes, ketones, pentafluorobutane; pentafluoropropane; hexafluoropropane; heptafluoropropane; trans-1,2 dichloroethylene; methylal, 1-chloro-1,2,2,2-tetrafluoroethane (HCFC-124); 1,1-dichloro-1-fluoroethane (HCFC-141b); 1,1,1,2-tetrafluoroethane (HFC-134a); 1,1,2,2-tetrafluoroethane (HFC-134); 1-chloro 1,1-difluoroethane (HCFC-142b); 1,1,1,3,3-pentafluorobutane (HFC-365mfc); 1,1,1,2,3,3,3-heptafluoropropane (HFC-227ea); trichlorofluoromethane (CFC-11); dichlorodifluoromethane (CFC-12); dichlorofluoromethane (HCFC-22); 1,1,1,3,3,3-hexafluoropropane (HFC-236fa); 1,1,1,2,3,3-hexafluoropropane (HFC-236e); 1,1,1,2,3,3,3-heptafluoropropane (HFC-227ea), difluoromethane (HFC-32); 1,1-difluoroethane (HFC-152a); 1,1,1,3,3-pentafluoropropane (HFC-245fa); 1,1,1,4,4,4-hexafluorobut-2-ene (HFO-1336mzzm—including its cis or “Z” isomer); butane; isobutene; C5 hydrocarbons (e.g. cyclopentane, n-pentane, iso-pentane, or the like); or combinations thereof.
The blowing agent of the present invention component is preferably present in the polyol premix composition in an amount of from about 1 wt. % to about 30 wt. %, preferably from about 3 wt. % to about 25 wt. %, and more preferably from about 5 wt. % to about 25 wt. %, by weight of the polyol premix composition. Such amounts result in a foam cell structure containing a gas that comprises in major proportion by weight, and in certain preferred embodiments consists essentially of, and in other preferred embodiments consists of, a combination of 1233zd(E) and methyl formate according to the present invention.
In general, the content of the gas in the resulting foam cell structure is dependent upon the component amounts of blowing agents used in the blend, and the relative percentage of the 1233zd(e) and methyl formate components in the blowing agent will preferably correspond substantially to the relative percentage in the gas contained in the cells upon initial formation of the foam.
The polyol component, which may include mixtures of polyols, can be any polyol which reacts in a known fashion with an isocyanate in preparing a polyurethane or polyisocyanurate foam. Useful polyols comprise one or more of a sucrose containing polyol; phenol, a phenol formaldehyde containing polyol; a glucose containing polyol; a sorbitol containing polyol; a methylglucoside containing polyol; an aromatic polyester polyol; glycerol; ethylene glycol; diethylene glycol; propylene glycol; graft copolymers of polyether polyols with a vinyl polymer; a copolymer of a polyether polyol with a polyurea; one or more of (a) condensed with one or more of (b): (a) glycerine, ethylene glycol, diethylene glycol, trimethylolpropane, ethylene diamine, pentaerythritol, soy oil, lecithin, tall oil, palm oil, castor oil; (b) ethylene oxide, propylene oxide, a mixture of ethylene oxide and propylene oxide; or combinations thereof. The polyol component is preferably present in the polyol premix composition in an amount of from about 60 wt. % to about 95 wt. %, preferably from about 65 wt. % to about 95 wt. %, and more preferably from about 70 wt. % to about 90 wt. %, by weight of the polyol premix composition.
In certain embodiments, the polyol premix composition may also contain at least one silicone-containing surfactant. The silicone-containing surfactant is used to aid in the formation of foam from the mixture, as well as to control the size of the bubbles of the foam so that a foam of a desired cell structure is obtained. Preferably, a foam with small bubbles or cells therein of uniform size is desired since it has the most desirable physical properties such as compressive strength and thermal conductivity. Also, it is critical to have a foam with stable cells which do not collapse prior to forming or during foam rise.
Silicone surfactants for use in the preparation of polyurethane or polyisocyanurate foams are available under a number of trade names known to those skilled in this art. Such materials have been found to be applicable over a wide range of formulations allowing uniform cell formation and maximum gas entrapment to achieve very low density foam structures. The preferred silicone surfactant comprises a polysiloxane polyoxyalkylene block co-polymer. Some representative silicone surfactants useful for this invention are Momentive's L-5130, L-5180, L-5340, L-5440, L-6100, L-6900, L-6980 and L-6988; Air Products DC-193, DC-197, DC-5582, and DC-5598; and B-8404, B-8407, B-8409 and B-8462 from Goldschmidt AG of Essen, Germany. Others are disclosed in U.S. Pat. Nos. 2,834,748; 2,917,480; 2,846,458 and 4,147,847, the contents of which are incorporated herein by reference. The silicone surfactant component is usually present in the polyol premix composition in an amount of from about 0.5 wt. % to about 5.0 wt. %, preferably from about 1.0 wt. % to about 4.0 wt. %, and more preferably from about 1.5 wt. % to about 3.0 wt. %, by weight of the polyol premix composition.
The polyol premix composition may optionally contain a non-silicone surfactant, such as a non-silicone, non-ionic surfactant. Such may include oxyethylated alkylphenols, oxyethylated fatty alcohols, paraffin oils, castor oil esters, ricinoleic acid esters, turkey red oil, groundnut oil, paraffins, and fatty alcohols. A preferred, but non-limiting, non-silicone non-ionic surfactant is LK-443 which is commercially available from Air Products Corporation. When a non-silicone, non-ionic surfactant used, it is present in the polyol premix composition in an amount of from about 0.05 wt. % to about 3.0 wt. %, preferably from about 0.05 wt. % to about 2.5 wt. %, and more preferably from about 0.1 wt. % to about 2.0 wt. %, by weight of the polyol premix composition.
The polyol premix composition may also include one or more catalysts, in particular amine catalysts and/or metal catalysts. Amine catalysts may include, but are not limited to, primary amine, secondary amine or tertiary amine. Useful tertiary amine catalysts non-exclusively include N,N,N′,N″,N″-pentamethyldiethyltriamine, N,N-dicyclohexylmethylamine; N,N-ethyldiisopropylamine; N,N-dimethylcyclohexylamine; N,N-dimethylisopropylamine; N-methyl-N-isopropylbenzylamine; N-methyl-N-cyclopentylbenzylamine; N-isopropyl-N-sec-butyl-trifluoroethylamine; N,N-diethyl-(α-phenylethyl)amine, N,N,N-tri-n-propylamine, or combinations thereof. Useful secondary amine catalysts non-exclusively include dicyclohexylamine; t-butylisopropylamine; di-t-butylamine; cyclohexyl-t-butylamine; di-sec-butylamine, dicyclopentylamine; di-(α-trifluoromethylethyl)amine; di-(α-phenylethyl)amine; or combinations thereof.
Useful primary amine catalysts non-exclusively include: triphenylmethylamine and 1,1-diethyl-n-propylamine.
Other useful amines includes morpholines, imidazoles, ether containing compounds, and the like. These include
dimorpholinodiethylether
bis(dimethylaminoethyl) ether
imidazole
n-methylimidazole
1,2-dimethylimidazole
dimorpholinodimethylether
N,N,N′,N′,N″,N″-pentamethyldiethylenetriamine
N,N,N′,N′,N″,N″-pentaethyldiethylenetriamine
N,N,N′,N′,N″,N″-pentamethyldipropylenetriamine
bis(diethylaminoethyl) ether
bis(dimethylaminopropyl) ether.
When an amine catalyst is used, it is present in the polyol premix composition in an amount of from about 0.05 wt. % to about 3.0 wt. %, preferably from about 0.05 wt. % to about 2.5 wt. %, and more preferably from about 0.1 wt. % to about 2.0 wt. %, by weight of the polyol premix composition.
Catalysts may also include one or a combination of metal catalysts, such as, but not limited to organometallic catalysts. The term organometallic catalyst refers to and is intended to cover in its broad sense both to preformed organometallic complexes and to compositions (including physical combinations, mixtures and/or blends) comprising metal carboxylates and/or amidines. In preferred embodiments, the catalyst of the present invention comprises: (a) one or more metal selected from the group consisting of zinc, lithium, sodium, magnesium, barium, potassium, calcium, bismuth, cadmium, aluminum, zirconium, tin, or hafnium, titanium, lanthanum, vanadium, niobium, tantalum, tellurium, molybdenum, tungsten, cesium; (b) in a complex and/or composition with an amidine compound; and/or (c) in a complex and/or composition with an aliphatic compound, aromatic compound and/or polymeric carboxylate.
Preferred among the amidine compounds for certain embodiments are those which contain catalytic amidine groups, particularly those having a heterocyclic ring (with the linking preferably being —N═C—N—), for example an imidazoline, imidazole, tetrahydropyrimidine, dihydropyrimidine or pyrimidine ring. Acyclic amidines and guanidines can alternatively be used. One preferred catalyst complex/composition comprises zinc (II), a methyl, ethyl, or propyl hexannoate, and a imidazole (preferably an lower alkylimidazole such as methylimidazole. Such catalysts may include Zn(1-methylimidazole)2(2-ethylhexannoate)2, together with, di-ethylene glycol, preferably as a solvent for the catalyst. To this end, one exemplified catalyst includes, but is not limited to, a catalyst sold under the trade designation K-Kat XK-614 by King Industries of Norwalk, Conn. Other catalysts include those sold under the trade designation Dabco K 15 and/or Dabco MB 20 by Air Products, Inc.
When one or a combination of metal catalysts are used, such a catalyst(s) is present in the polyol premix composition in an amount of from about 0.5 wt. % to about 10 wt. %, or preferably from about 1.0 wt. % to about 8.0 wt. % by weight of the polyol premix composition.
The preparation of polyurethane or polyisocyanurate foams using the compositions described herein may follow any of the methods well known in the art can be employed, see Saunders and Frisch, Volumes I and II Polyurethanes Chemistry and technology, 1962, John Wiley and Sons, New York, N.Y. or Gum, Reese, Ulrich, Reaction Polymers, 1992, Oxford University Press, New York, N.Y. or Klempner and Sendijarevic, Polymeric Foams and Foam Technology, 2004, Hanser Gardner Publications, Cincinnati, Ohio. In general, polyurethane or polyisocyanurate foams are prepared by combining an isocyanate, the polyol premix composition, and other materials such as optional flame retardants, water, colorants, or other additives. These foams can be rigid, flexible, or semi-rigid, and can have a closed cell structure, an open cell structure or a mixture of open and closed cells.
It is convenient in many applications to provide the components for polyurethane or polyisocyanurate foams in pre-blended formulations. Most typically, the foam formulation is pre-blended into two components. The isocyanate and optionally other isocyanate compatible raw materials, including but not limited to blowing agents and certain silicone surfactants, comprise the first component, commonly referred to as the “A” component. The polyol mixture composition, including surfactant, catalysts, blowing agents, and optional other ingredients comprise the second component, commonly referred to as the “B” component. In any given application, the “B” component may not contain all the above listed components, for example some formulations omit the flame retardant if flame retardancy is not a required foam property. Accordingly, polyurethane or polyisocyanurate foams are readily prepared by bringing together the A and B side components either by hand mix for small preparations and, preferably, machine mix techniques to form blocks, slabs, laminates, pour-in-place panels and other items, spray applied foams, froths, and the like. Optionally, other ingredients such as fire retardants, colorants, auxiliary blowing agents, water, and even other polyols can be added as a stream to the mix head or reaction site. Most conveniently, however, they are all, with the exception of water, incorporated into one B component as described above.
A foamable composition suitable for forming a polyurethane or polyisocyanurate foam may be formed by reacting an organic polyisocyanate and the polyol premix composition described above. Any organic polyisocyanate can be employed in polyurethane or polyisocyanurate foam synthesis inclusive of aliphatic and aromatic polyisocyanates. Suitable organic polyisocyanates include aliphatic, cycloaliphatic, araliphatic, aromatic, and heterocyclic isocyanates which are well known in the field of polyurethane chemistry. These are described in, for example, U.S. Pat. Nos. 4,868,224; 3,401,190; 3,454,606; 3,277,138; 3,492,330; 3,001,973; 3,394,164; 3,124.605; and 3,201,372. Preferred as a class are the aromatic polyisocyanates.
Representative organic polyisocyanates correspond to the formula:
R(NCO)z
wherein R is a polyvalent organic radical which is either aliphatic, aralkyl, aromatic or mixtures thereof, and z is an integer which corresponds to the valence of R and is at least two. Representative of the organic polyisocyanates contemplated herein includes, for example, the aromatic diisocyanates such as 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, mixtures of 2,4- and 2,6-toluene diisocyanate, crude toluene diisocyanate, methylene diphenyl diisocyanate, crude methylene diphenyl diisocyanate and the like; the aromatic triisocyanates such as 4,4′,4″-triphenylmethane triisocyanate, 2,4,6-toluene triisocyanates; the aromatic tetraisocyanates such as 4,4′-dimethyldiphenylmethane-2,2′5,5-′tetraisocyanate, and the like; arylalkyl polyisocyanates such as xylylene diisocyanate; aliphatic polyisocyanate such as hexamethylene-1,6-diisocyanate, lysine diisocyanate methylester and the like; and mixtures thereof. Other organic polyisocyanates include polymethylene polyphenylisocyanate, hydrogenated methylene diphenylisocyanate, m-phenylene diisocyanate, naphthylene-1,5-diisocyanate, 1-methoxyphenylene-2,4-diisocyanate, 4,4′-biphenylene diisocyanate, 3,3′-dimethoxy-4,4′-biphenyl diisocyanate, 3,3′-dimethyl-4,4′-biphenyl diisocyanate, and 3,3′-dimethyldiphenylmethane-4,4′-diisocyanate; Typical aliphatic polyisocyanates are alkylene diisocyanates such as trimethylene diisocyanate, tetramethylene diisocyanate, and hexamethylene diisocyanate, isophorene diisocyanate, 4, 4′-methylenebis(cyclohexyl isocyanate), and the like; typical aromatic polyisocyanates include m-, and p-phenylene disocyanate, polymethylene polyphenyl isocyanate, 2,4- and 2,6-toluenediisocyanate, dianisidine diisocyanate, bitoylene isocyanate, naphthylene 1,4-diisocyanate, bis(4-isocyanatophenyl)methene, bis(2-methyl-4-isocyanatophenyl)methane, and the like. Preferred polyisocyanates are the polymethylene polyphenyl isocyanates, Particularly the mixtures containing from about 30 to about 85 percent by weight of methylenebis(phenyl isocyanate) with the remainder of the mixture comprising the polymethylene polyphenyl polyisocyanates of functionality higher than 2. These polyisocyanates are prepared by conventional methods known in the art. In the present invention, the polyisocyanate and the polyol are employed in amounts which will yield an NCO/OH stoichiometric ratio in a range of from about 0.9 to about 5.0. In the present invention, the NCO/OH equivalent ratio is, preferably, about 1.0 or more and about 3.0 or less, with the ideal range being from about 1.1 to about 2.5. Especially suitable organic polyisocyanate include polymethylene polyphenyl isocyanate, methylenebis(phenyl isocyanate), toluene diisocyanates, or combinations thereof.
In the preparation of polyisocyanurate foams, trimerization catalysts are used for the purpose of converting the blends in conjunction with excess A component to polyisocyanurate-polyurethane foams. The trimerization catalysts employed can be any catalyst known to one skilled in the art, including, but not limited to, glycine salts, tertiary amine trimerization catalysts, quaternary ammonium carboxylates, and alkali metal carboxylic acid salts and mixtures of the various types of catalysts. Preferred species within the classes are potassium acetate, potassium octoate, and N-(2-hydroxy-5-nonylphenol)methyl-N-methylglycinate.
Conventional flame retardants can also be incorporated, preferably in amount of not more than about 20 percent by weight of the reactants. Optional flame retardants include tris(2-chloroethyl)phosphate, tris(2-chloropropyl)phosphate, tris(2,3-dibromopropyl)phosphate, tris(1,3-dichloropropyl)phosphate, tri(2-chloroisopropyl)phosphate, tricresyl phosphate, tri(2,2-dichloroisopropyl)phosphate, diethyl N,N-bis(2-hydroxyethyl) aminomethylphosphonate, dimethyl methylphosphonate, tri(2,3-dibromopropyl)phosphate, tri(1,3-dichloropropyl)phosphate, and tetra-kis-(2-chloroethyl)ethylene diphosphate, triethylphosphate, diammonium phosphate, various halogenated aromatic compounds, antimony oxide, aluminum trihydrate, polyvinyl chloride, melamine, and the like. Other optional ingredients can include from 0 to about 7 percent water, which chemically reacts with the isocyanate to produce carbon dioxide. This carbon dioxide acts as an auxiliary blowing agent. In the case of this invention, the water cannot be added to the polyol blend but, if used, can be added as a separate chemical stream. Formic acid is also used to produce carbon dioxide by reacting with the isocyanate and is optionally added to the “B” component.
In addition to the previously described ingredients, other ingredients such as, dyes, fillers, pigments and the like can be included in the preparation of the foams. Dispersing agents and cell stabilizers can be incorporated into the present blends. Conventional fillers for use herein include, for example, aluminum silicate, calcium silicate, magnesium silicate, calcium carbonate, barium sulfate, calcium sulfate, glass fibers, carbon black and silica. The filler, if used, is normally present in an amount by weight ranging from about 5 parts to 100 parts per 100 parts of polyol. A pigment which can be used herein can be any conventional pigment such as titanium dioxide, zinc oxide, iron oxide, antimony oxide, chrome green, chrome yellow, iron blue siennas, molybdate oranges and organic pigments such as para reds, benzidine yellow, toluidine red, toners and phthalocyanines.
The polyurethane or polyisocyanurate foams produced can vary in density from about 0.5 pounds per cubic foot to about 60 pounds per cubic foot, preferably from about 1.0 to 20.0 pounds per cubic foot, and most preferably from about 1.5 to 6.0 pounds per cubic foot. The density obtained is a function of how much of the blowing agent or blowing agent mixture disclosed in this invention plus the amount of auxiliary blowing agent, such as water or other co-blowing agents is present in the A and/or B components, or alternatively added at the time the foam is prepared. These foams can be rigid, flexible, or semi-rigid foams, and can have a closed cell structure, an open cell structure or a mixture of open and closed cells. These foams are used in a variety of well known applications, including but not limited to thermal insulation, cushioning, flotation, packaging, adhesives, void filling, crafts and decorative, and shock absorption.
Among many uses, the foams of the present invention may be used to insulate buildings (e.g. building envelope) or any construction where energy management and/or insulation from temperature fluctuations on its exterior side are desirable. Such structures include any standard structure known in the art including, but not limited to those, manufactured from clay, wood, stone, metals, plastics, cement, or the like, including, but not limited to homes, office buildings, or other structures residential, commercial, or otherwise were energy efficiency and insulation may be desirable.
In one non-limiting aspect of the invention, a two or more part foamable composition in accordance with the foregoing embodiments may be provided. The components of a two part system, commonly referred to as the A-side and the B-side may be delivered through separate lines into a mixing head, such as a high pressure impingement-type mixer or a low pressure mechanical type mixer. In those applications where more than two components are used, the components are provided through separate lines into a mixing head, such as a high pressure impingement-type mixer or a low pressure mechanical type mix head. The streams of the first, second and optionally additional component streams intersect in the mix head and mix with each other either by direct impingement of the high pressure component streams or by mechanical mixing of the low pressure component streams. Because the components are under pressure inside the mix head, the blowing agent does not vaporize. However, as the mixture exits the mix head and enters into atmospheric pressure, the blowing agent vaporizes as reaction of the polyisocyanate and polyol (to form the polyurethane or polyisocyanurate) occurs. Crosslinking and molecular weight captures the bubbles generated by the evolution of the gas before they can coalesce and escape and forms cells that provide the insulative function.
Such foams, in certain embodiments, may be produced in a discontinuous or a continuous process. In a discontinuous process, individual panel or other parts are produced in a mold or other suitable device. In continuous processes, the foamable mixture is dispensed onto a moving conveyor and allowed to rise between the upper and lower facers of the panel. Typical facers include aluminum foil, roofing felt, aluminum, steel, particle board, plywood, FRP or other similar materials. In certain preferred embodiments, the foams of the present invention may be used to insulate a building envelope such as a house, commercial building, or the like. In alternative embodiments, the foams of the present invention may serve as a roofing insulation for flat or pitched roofs, as walls, ceilings, and floors in residential, commercial, governmental, and industrial buildings. In yet other embodiments, the foam panels may be used to insulate and provide structure to cold storage buildings, walk in coolers and freezers, insulated transportation container, such as rail cars, trucks, and iso containers, and the like.
The following non-limiting examples serve to illustrate the invention.
Table 1 and Table 2, below, list the properties of 1233zd(E) and 1234ze(E) compared to other commonly used blowing agents. Note that 1233zd(E) exhibits certain key physical properties, such as boiling point and flammability, similar to 245fa and with certain advantages compared to cyclopentane or 365mfc.
The GWP of 1233zd(E) of <7, is more than two orders of magnitude lower than that of currently utilized HFCs, and is more than one order of magnitude lower than the present limitations in the EU F-Gas Regulation. 1234ze(E) has properties similar to 134a. Like 1233zd(E), the GWP of 1234ze(E) of <6 is more than two orders of magnitude lower than 134a and is within the EU F-Gas Regulation limit.
12007 Technical Summary. Climate Change 2007: They Physical Science Basis. Contribution of Working Group 1 to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. (except where noted)
2Generally accepted value
3Manufacturers' literature expect where noted
12007 Technical Summary. Climate Change 2007: They Physical Science Basis. Contribution of Working Group 1 to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. (except where noted)
2Manufacturers' literature expect where noted
Table 3A and Table 3B list the properties of 1233zd(E) compared to some non-flammable blowing agents, such as 245fa and 141b, and various flammable blowing agents, such as methyl formate and hydrocarbons. Note that the 1233zd(E) exhibits certain physical properties, such as boiling point and flammability, similar to those of 245fa and superior to those of methyl formate or hydrocarbons. Note that the global warming potential (GWP) of 1233zd(E) of less than 5 is the lowest among all blowing agents compared. Moreover, the GWP of 1233zd(E) is more than two orders of magnitude lower than that of the currently utilized 245fa, and is more than one order of magnitude lower than the present limitations in the EU F-Gas Regulation.
1Climate Change 2007: The Physical Science Basis. Contribution of Working Group 1 to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change.
2Private Correspondence with Donald Wuebbles
3Transitioning to LOW-GWP Alternatives in Domestic Refrigeration, http://www.epa.gov/ozone/downloads/EPA_HFC_DomRef.pdf
4Manufacturers' literature
5Honeywell internal PEL
1Climate Change 2007: The Physical Science Basis. Contribution of Working Group 1 to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change.
2Private Correspondence with Donald Wuebbles
3Transitioning to LOW-GWP Alternatives in Domestic Refrigeration, http://www.epa.gov/ozone/downloads/EPA_HFC_DomRef.pdf
4Manufacturers' literature
5Honeywell internal PEL
In the experiments below, all foams were prepared utilizing an Edge-Sweets high pressure foam machine with processing conditions given in Table 4. Polyol premix and isocyanate were mixed through an impingement mechanism at the head while the mixture shot into a mold preheated to 120° F. to 125° F., and allowed to cure in a 130° F. oven for 20 minutes before demolding. All physical property and thermal conductivity testing was performed at least 24 hours after the foam was prepared.
A generic polyurethane foam formulation with 1233zd(E) and components that can be easily sourced in the US is listed in Table 5. This generic formulation was developed to yield a free rise density of about 1.9 lb/ft3. With approximately 20% overpack. The density of the prepared foams ranged from 2.2 lb/ft3 to 2.3 lb/ft3. The amount of each of the blowing agent blends were calculated such that the total moles of blowing agent in the formulation were constant. This experiment is considered as a “drop-in” replacement study to determine the blowing agent blends' feasibility. The formulation was not optimized for any particular blowing agent that was used in this study.
The free rise density and core density of the polyurethane foams prepared with methyl formate or 1233zd(E)/methyl formate blowing agent blends are within a 10% range of each other, as shown in Table 6. With the insignificant difference in density, comparisons of their physical, thermal properties are considered as fair and valid.
The initial and 28-day thermal conductivity of foams with various 1233zd(E)/methyl formate blends are shown in
Table 8 summarizes physical properties, such as dimensional stability and compressive strength, of foam with various ratios of 1233zd(E)/methyl formate blends. Foams were evaluated after 28 days aging at −29° C., 90° C. and 70° C./95% relative humidity as per ASTM D-2126-09. Furthermore, the compressive strength of foams was tested at both parallel and perpendicular directions as per ASTM D-1621-10.
1Dimensional stability of foam was evaluated as per ASTM D-2126-09
2Compressive strength of foam was evaluated as per ASTM D-1621-10
As shown in
All foams were evaluated for flammability performance using the DIN 4102 B2 test method. In order to pass the DIN 4102-1: Class B2 material evaluation, the flame height could not surpass the gauge located 15 cm above the ignition point, during the first 15 seconds of the test.
1Flammability of foams was evaluated as per DIN 4102-1: Class B2 Materials
According to Table 9, foam with 1233zd(E) has the best flame retardancy when compared to those with any of the 1233zd(E)/hydrocarbon blends and 1233zd(E)/methyl formate blends evaluated. For foams with hydrocarbons, unlike that with cyclopentane, those with isopentane and n-pentane have failed the B2 evaluation requirements. From the data, adding 1233zd(E) improves the flame retardancy of foams with isopentane, n-pentane or cyclopentane. Although, foams with methyl formate passed the evaluation, a similar foam flammability improvement was not observed when 1233zd(E) was blended with methyl formate.
The present application claims priority to: U.S. Continuation application Ser. No. 14/362,495, filed on Jun. 3, 2014, and U.S. Provisional application Ser. No. 61/569,061, filed on Dec. 9, 2011, the contents of each of which are incorporated herein by reference in their entirety.
| Number | Date | Country | |
|---|---|---|---|
| 61569061 | Dec 2011 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 14362495 | Jun 2014 | US |
| Child | 16025633 | US |
