Blowing agent compositions for insulating foams

Abstract

To provide a polymer foam having improved thermal insulation properties.SOLUTION: The present invention provides a blowing agent composition for polymer foams, comprising a) a hydrofluoroolefin (HFO) blowing agent and b) a branched hydrocarbon co-blowing agent, the composition being substantially free of water.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to and the benefit of U.S. Provisional Patent Application No. 62 / 677,248, filed May 29, 2018, the entire contents of which are incorporated herein by reference. The present invention relates to blowing agent compositions for insulating foams made from thermoplastic polymers. The present invention further relates to insulating foams made utilizing these blowing agent compositions. [Background technology]

[0002] Insulating foam has traditionally been made using halogenated blowing agents to create gas-filled cells within the insulating foam. The earliest blowing agents included chlorofluorocarbons (CFCs) and chlorofluorohydrocarbons (HCFCs). However, environmental concerns regarding chlorinated blowing agents, including potential ozone depletion in the upper atmosphere, led to the development of blowing agents that were deemed less damaging to the environment. These later blowing agents included fluorocarbons (FCs) and fluorohydrocarbons (HFCs). In recent years, new hydrofluoroolefins (HFOs) have been developed. HFO blowing agents are considered more environmentally friendly than traditional halogenated blowing agents. For example, HFOs are considered to have reduced ozone depletion potential (ODP) and reduced global warming potential (GWP) compared to traditional FC and HFC halogenated blowing agents.

[0003] Other types of blowing agents besides halogenated ones are being investigated. For example, hydrocarbons such as pentane, hexane, cyclopentane, and similar compounds are also being considered as blowing agents. These hydrocarbons are highly flammable and volatile, raising both safety concerns and concerns about volatile organic compound (VOC) emissions. Carbon dioxide (CO2) is an attractive candidate blowing agent from both an environmental and economic standpoint. CO2 has relatively low solubility in polymers typically used as matrix polymers for insulation foams, high diffusivity, and poor processability, making it difficult to use CO2 advantageously as a blowing agent. CO2 also has a higher thermal conductivity than HCFCs and HFCs, and foams blown with CO2 exhibit insulation values ​​approximately 10–20% lower than those produced with HCFCs or HFCs. To ensure that the insulating foam has the desired properties (e.g., low density, good thermal resistance, etc.), it is important that the blowing agent be sufficiently soluble in the insulating foam's polymer matrix. It has been found that HFO blowing agents alone may not be sufficiently soluble in the insulating foam's polymer matrix, resulting in insulating foams that are too dense or have unacceptably high thermal conductivity. Blowing agent compositions containing combinations of HFOs with HCFCs, HFCs, carbon dioxide, water, and other such mixtures have been attempted to improve the properties of the resulting insulating foams, with varying results. Summary of the Invention

[0004] Objects of the present invention include improved blowing agent compositions comprising HFOs and branched hydrocarbons. Objects further include foamable polymer compositions incorporating the improved blowing agents, and improved methods of making polymer foams using the improved blowing agents. In some exemplary embodiments, the blowing agent is substantially free of water. In exemplary embodiments of the present invention, a foamable polymer composition is provided that includes a matrix polymer and a blowing agent composition that includes an HFO and a branched hydrocarbon. In some exemplary embodiments, the foamable polymer composition is substantially free of water.

[0005] In exemplary embodiments of the present invention, a method for producing a polymer foam is provided, the method comprising the steps of melting a matrix polymer, mixing the matrix polymer melt with a blowing agent composition comprising an HFO and a branched hydrocarbon to form a foamable polymer composition, and extruding the foamable polymer composition to form a polymer foam. In some exemplary embodiments, the foamable polymer composition is substantially free of water. Exemplary embodiments of the invention will become apparent from the more detailed description of certain exemplary embodiments of the invention provided below and illustrated in the accompanying drawings. [Brief explanation of the drawings]

[0006] [Figure 1] 1 is a graph of the thermal insulation properties of foam formulations containing various blowing agent compositions after 7 days of aging. [Figure 2] 1 is a graph of the thermal insulation properties of foam formulations containing various concentrations of HFO-1234ze and n-pentane as the foam ages. [Figure 3] 1 is a graph of the thermal insulation properties of foam formulations containing HFO-1234ze and various co-blowing agents as the foam ages. [Figure 4] 4 is a graph of the data from FIG. 3 normalized by the mole percent concentration of each co-blowing agent. [Figure 5] 1 is a graph of the thermal insulation properties of foam formulations containing HFO-1234ze and isobutane at various densities as the foam ages. [Figure 6] 1 is a graph of the thermal insulation properties of foam formulations of various densities containing HFO-1234ze and various hydrocarbon co-blowing agents after 7 days aging. [Figure 7]1 is a graph of the thermal insulation properties of foam formulations containing HFO-1234ze, isobutane, and carbon dioxide. DETAILED DESCRIPTION OF THE INVENTION

[0007] These drawings are provided to facilitate understanding of example embodiments of the invention, which are described in more detail below, and should not be construed as unduly limiting the invention. Polymer foam compositions are described in detail herein, along with methods for making the polymer foams. The compositions and methods for making the polymer foams disclosed herein include a blowing agent composition comprising a hydrofluoroolefin (HFO) and a branched hydrocarbon. In some exemplary embodiments, the blowing agent is substantially free of water and carbon dioxide. The resulting polymer foams have reduced thermal conductivity and therefore improved insulating properties compared to blowing agents comprising HFOs and linear hydrocarbons. These and other features of the polymer foams, as well as some of the many optional variations and additions, are described in detail below.

[0008] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this invention belongs. Any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention. Any reference cited herein, including published or corresponding U.S. or foreign patent applications, issued U.S. or foreign patents, or any other references, is each incorporated by reference in its entirety, including all data, tables, figures, and text presented in the cited reference. As used in describing this invention and in the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms unless the context clearly indicates otherwise. When the term "includes" or "including" is used in this specification or in the claims, it is intended to be inclusive in the same manner as the term "comprising" is interpreted when used as a transitional term in the claims. Furthermore, when the term "or" is used (e.g., A or B), it is intended to mean "A or B or both." When applicants intend to indicate "only A or B, but not both," the term "only A or B, but not both" is used. Thus, the use of the term "or" herein is inclusive, not exclusive.

[0009] Numerical ranges used herein are intended to include every number and subset of numbers within the range, whether or not specifically disclosed. Furthermore, these numerical ranges should be construed to support claims directed to any number or subset of numbers within that range. For example, a disclosure of 1 to 10 should be construed to support ranges of 2 to 8, 3 to 7, 5 to 6, 1 to 9, 3.6 to 4.6, 3.5 to 9.9, etc. Any reference in this disclosure to a singular feature or limitation is intended to include the corresponding plural feature or limitation, and vice versa, unless otherwise specified or clearly indicated to the contrary by the context in which the reference is made. As used herein, unless otherwise specified, values ​​for components or ingredients of a polymer foam, flame retardant composition, or other composition are expressed in weight percent or weight % of each component of the composition. The values ​​provided are inclusive up to and including the endpoints given. Unless otherwise specified, the terms "% by weight" and "% by weight (wt.%)" are used interchangeably and are intended to indicate a percentage of a total weight of 100%. In some embodiments, the amount of blowing agent is given in moles / 100g, which is intended to indicate the number of moles of the specified blowing agent per 100 grams of matrix polymer.

[0010] As used herein, the term "polymer" is generic to the terms "homopolymer," "copolymer," "terpolymer," and combinations of homopolymers, copolymers, and / or terpolymers. As used herein, the term "matrix polymer" refers to the polymer or polymer mixture that forms the bulk of the foamable polymer composition and the polymer foam product. The matrix polymer provides strength, flexibility, toughness, and durability to the final product. As used herein, the term "matrix polymer composition" refers to a composition comprising a matrix polymer and other optional additives such as stabilizers, processing aids, colorants, fire retardants, and the like. As used herein, the term "blowing agent" refers to a liquid or gaseous compound or mixture that, when mixed with a molten matrix polymer composition under pressure (such as the pressure in an extruder), forms a foamable polymer composition and, when the composition is released from the pressure, transforms into small gas pockets, thereby foaming the foamable polymer composition. As used herein, the term "co-blowing agent" refers to a second (third, fourth, etc.) blowing agent in a blowing agent composition.

[0011] As used herein, the term "branched hydrocarbon" refers to a compound composed of carbon and halogen atoms, wherein the carbon atoms are arranged in a branched configuration rather than in a linear or cyclic configuration. Exemplary branched hydrocarbons include isobutane, isopentane, neopentane, isohexane, 3-methylpentane, 2,3-dimethylbutane, neohexane, isoheptane, 3-methylhexane, 2,2-dimethylpentane, 2,3-dimethylpentane, 2,4-dimethylpentane, 3,3-dimethylpentane, 3-ethylpentane, and 2,2,3-trimethylbutane. Typical procedures utilized in the preparation of extruded synthetic foams generally involve melting a matrix polymer composition and then incorporating a blowing agent composition into the polymer melt to form a foamable polymer composition under conditions that result in thorough mixing of the blowing agent composition with the matrix polymer while simultaneously preventing the foamable polymer composition from prematurely foaming, e.g., under pressure. Other additives (e.g., stabilizers, processing aids, colorants, fire retardants, etc.) may also be added to the foamable polymer composition. This foamable polymer composition is then typically extruded through a single- or multi-stage extrusion die that cools and depressurizes the foamable polymer composition, causing it to expand and produce a foam product. As will be appreciated, the relative amounts of polymer, blowing agent, and additives in the foamable polymer composition, as well as the temperature and manner of depressurization, can affect the quality and properties of the resulting foam product.

[0012] Foaming agent composition The solubility of the blowing agent composition in the matrix polymer is an important consideration when selecting a blowing agent composition. For example, combinations of pentane and CFCs such as Freon 11 and 12 are partially soluble in PS and have been used to produce PS foams that generally exhibit acceptable appearance and physical properties such as surface finish, cell size and distribution, orientation, shrinkage, and hardness. Fluorocarbons (FCs) and hydrofluorocarbons (HFCs) such as 1,1,1,2-tetrafluoroethane (HFC-134a) and 1,1-difluoroethane (HFC-152a) are considered much more ozone-friendly than CFCs, but tend to have low solubility in PS. Newer hydrofluoroolefin (HFO) blowing agents are considered more environmentally friendly than traditional halogenated blowing agents. However, many HFOs, such as tetrafluoropropene, have poor solubility in PS. When these HFOs are used as blowing agents without a co-blowing agent to make PS foams, the HFOs tend to remain undissolved in the PS matrix, which leads to large blowholes and other defects in the foam product upon extrusion of the foamable polymer composition. The poor solubility of HFO blowing agents in PS can also have a detrimental effect on the long-term insulating properties of the foam.

[0013] HFO blowing agents with co-blowing agents such as hydrocarbons, hydrofluorocarbons, carbon dioxide, and water have been studied to determine whether the co-blowing agents improve the solubility of the HFO in the matrix polymer. Hydrocarbons are soluble in PS and are thought to also improve the solubility of HFO in PS. The inventors have unexpectedly discovered that HFO blowing agent compositions containing a branched hydrocarbon co-blowing agent produce foams with improved insulation properties compared to foams made with blowing agent compositions containing an HFO and a linear hydrocarbon, a cyclic hydrocarbon, or an HFC co-blowing agent, but no branched hydrocarbon. Without wishing to be bound by theory, the inventors believe that branched hydrocarbons are superior co-blowing agents due to the compactness of the branched hydrocarbon molecules. The pendant branching groups (e.g., methyl groups) on the branched hydrocarbons mean that these molecules are more compact and have a smaller surface area than linear or cyclic hydrocarbon molecules with the same number of carbon atoms. The intermolecular attraction, which depends on the molecular surface area, is also weaker between branched hydrocarbons than between linear or cyclic hydrocarbons with the same number of carbon atoms. As a result, the boiling points of branched hydrocarbons are lower than their linear or cyclic counterparts, and the lower boiling points result in an increased vapor pressure of the branched hydrocarbons. The increased vapor pressure of the branched hydrocarbons increases the branched hydrocarbon gas within each cell of the insulation foam. Because the blowing agent must be in gaseous form to be an effective insulating gas, increasing the vapor pressure of the blowing agent, and therefore the gas within the foam cells, tends to improve insulation.

[0014] Examples of the hydrofluoroolefin blowing agent for the blowing agent composition of the present invention include 3,3,3-trifluoropropene (HFO-1243zf), 2,3,3-trifluoropropene, (cis and / or trans)-1,3,3,3-tetrafluoropropene (HFO-1234ze), particularly the trans isomer, 1,1,3,3-tetrafluoropropene, 2,3,3,3-tetrafluoropropene (HFO-1234yf), (cis and / or trans)-1,2,3,3,3-pentafluoropropene (HFO-1225ye), 1,1,3 ,3,3-Pentafluoropropene (HFO-1225zc), 1,1,2,3,3-Pentafluoropropene (HFO-1225yc), hexafluoropropene (HFO-1216), 2-fluoropropene, 1-fluoropropene, 1,1-difluoropropene, 3,3-difluoropropene, 4,4,4-trifluoro-1-butene, 2,4,4,4-tetrafluoro-1-butene, 3,4,4,4-tetrafluoro-1-butene, octafluoro-2-pentene (HFO-1438), 1,1,3,3,3-pentafluoro-2-methyl -l-Propene, octafluoro-1-butene, 2,3,3,4,4,4-hexafluoro-1-butene, 1,1,1,4,4,4-hexafluoro-2-butene (HFO-1336 m / z), 1,2-difluoroethene (HFO-1132), 1,1,1,2,4,4,4-heptafluoro-2-butene, 3-fluoropropene, 2,3-difluoropropene, 1,1,3-trifluoropropene, 1,3,3-trifluoropropene, 1,1,2-trifluoropropene, 1-fluorobutene, 2-fluorobutene, 2-fluoro-2-butene , 1,1-difluoro-1-butene, 3,3-difluoro-1-butene, 3,4,4-trifluoro-1-butene, 2,3,3-trifluoro-1-butene, 1,1,3,3-tetrafluoro-1-butene, 1,4,4,4-tetrafluoro-1-butene, 3,3,4,4-tetrafluoro-1-butene, 4,4-difluoro-1-butene, 1,1,1-trifluoro-2-butene, 2,4,4,4-tetrafluoro-1-butene, 1,1,1,2-tetrafluoro-2-butene, 1,1,4,4,4-pentafluoro-1-butene, 2,3,3,4,Examples include 4-pentafluoro-1-butene, 1,2,3,3,4,4,4-heptafluoro-1-butene, 1,1,2,3,4,4,4-heptafluoro-1-butene, and 1,3,3,3-tetrafluoro-2-(trifluoromethyl)-propene. In some exemplary embodiments, the blowing agent or co-blowing agent includes HFO-1234ze.

[0015] The branched hydrocarbon co-blowing agent of the blowing agent composition of the present invention can include, for example, branched butane, pentane, hexane, and heptane. Preferred branched hydrocarbon co-blowing agents include, but are not limited to, isobutane, isopentane, neopentane, isohexane, 3-methylpentane, 2,3-dimethylbutane, neohexane, isoheptane, 3-methylhexane, 2,2-dimethylpentane, 2,3-dimethylpentane, 2,4-dimethylpentane, 3,3-dimethylpentane, 3-ethylpentane, and 2,2,3-trimethylbutane. In some exemplary embodiments, the blowing agent or co-blowing agent includes isobutane, isopentane, or a combination thereof.

[0016] In certain exemplary embodiments, the HFO blowing agent comprises from about 14% to about 89% by weight of the total weight of the blowing agent composition, for example, from about 15% to about 80% by weight of the total weight of the blowing agent composition, for example, from about 20% to about 75% by weight, for example, from about 25% to about 70% by weight, for example, from about 30% to about 65% by weight, for example, from about 35% to about 60% by weight, for example, from about 38% to about 55% by weight. In some exemplary embodiments, the HFO blowing agent comprises less than 50% by weight of the total blowing agent composition. In certain exemplary embodiments, the branched hydrocarbon co-blowing agent comprises from about 5.0% to about 85% by weight of the total weight of the blowing agent composition, such as from about 7.0% to about 50%, for example, from about 9.0% to about 45%, for example, from about 10% to about 40%, for example, from about 12% to about 35%, for example, from about 12.3% to about 32%, for example, from about 12.5% ​​to about 30%.

[0017] In certain exemplary embodiments, the blowing agent composition further comprises at least one second co-blowing agent, such as one or more hydrofluorocarbons ("HFCs"), hydrochlorofluorocarbons ("HCFOs"), carbon dioxide, and water. In some exemplary embodiments, the blowing agent composition comprises two or more second co-blowing agents, such as a hydrofluorocarbon and carbon dioxide. In some exemplary embodiments, the blowing agent composition does not comprise a second co-blowing agent. In some exemplary embodiments, the blowing agent formulation does not comprise carbon dioxide and / or water. In various exemplary embodiments, the blowing agent composition does not comprise a hydrofluorocarbon.

[0018] In some exemplary embodiments, the second co-blowing agent may comprise one or more hydrofluorocarbons. The particular hydrofluorocarbons utilized are not particularly limited. A non-exhaustive list of examples of suitable blowing HFC blowing agents includes 1,1-difluoroethane (HFC-152a), 1,1,1,2-tetrafluoroethane (HFC-134a), 1,1,2,2-tetrafluoroethane (HFC-134), 1,1,1-trifluoroethane (HFC-143a), difluoromethane (HFC-32), 1,3,3,3-pentafluoropropane (HFO-1234ze), pentafluoroethane (HFC-125), fluoroethane (HFC-161), 1,1,2,2,3,3-hexafluoropropane (HFC-236ca), 1,1,1,2,3,3-hexafluoroethane (HFC-236ca), and 1,1,1,2,3,3-hexafluoroethane (HFC-236ca). In some exemplary embodiments, the second co-blowing agent may include HFC-152a, 1,1,1,3,3,3-hexafluoropropane (HFC-236ea), 1,1,1,3,3,3-hexafluoropropane (HFC-236fa), 1,1,1,2,2,3-hexafluoropropane (HFC-245ca), 1,1,2,3,3-pentafluoropropane (HFC-245ea), 1,1,1,2,3-pentafluoropropane (HFC-245eb), 1,1,1,3,3-pentafluoropropane (HFC-245fa), 1,1,1,4,4,4-hexafluorobutane (HFC-356mff), 1,1,1,3,3-pentafluorobutane (HFC-365mfc), and combinations thereof.

[0019] The second co-blowing agent may also be HCFO-1233, 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-pentafluoroethane (HCFC-143a), 1,1,1,3,3-pentafluoroethane (HCFC-143b), 1,1,1,3,3-pentafluoroethane (HCFC-143c), 1,1,1,3,3-pentafluoroethane (HCFC-143d), 1,1,1,3,3-pentafluoroethane (HCFC-143e), 1,1,1,3,3-pentafluoroethane (HCFC-143f ... It may also include one or more hydrochlorofluoroolefins (HCFOs), such as fluorobutane (HFC-365mfc), 1,1,1,2,3,3,3-heptafluoropropane (HFC-227ea), trichlorofluoromethane (CFC-11), dichlorodifluoromethane (CFC-12), and dichlorofluoromethane (HCFC-22). The term "HCFO-1233" is used herein to refer to all trifluoromonochloropropenes. Trifluoromonochloropropenes include both cis and trans 1,1,1-trifluoro-3,chloropropene (HCFO-1233zd or 1233zd). The term "HCFO-1233zd" or "1233zd" is used herein to refer generally to 1,1,1-trifluoro-3-chloro-propene, regardless of whether it is the cis or trans form. The terms "cisHCFO-1233zd" and "trans-1233zd" are used herein to describe the cis and trans forms or trans isomers of 1,1,1-trifluoro-3-chloropropene, respectively.

[0020] In certain exemplary embodiments, the second co-blowing agent comprises from 0 to about 90% by weight of the blowing agent composition, e.g., from about 0.5% to about 89% by weight of the total weight of the blowing agent composition, e.g., from about 1% to about 50% by weight of the total weight of the blowing agent composition, e.g., from about 3% to about 25% by weight, e.g., from about 5% to about 20% by weight, e.g., from about 7% to about 15% by weight, e.g., from about 7.5% to about 13% by weight. In certain exemplary embodiments, the total blowing agent composition is present in an amount of from about 2% to about 15% by weight, and in some embodiments, from about 3% to about 10% by weight, or from about 4% to about 9% by weight (based on the total weight of the foamable composition excluding the blowing agent composition). In some exemplary embodiments, the total blowing agent composition is present in an amount of from about 6.8% to about 8.0% by weight, such as from about 7.3% to about 7.9% by weight, based on the total weight of the foamable composition excluding the blowing agent composition. In certain exemplary embodiments, the HFO blowing agent comprises from about 1% to about 8% by weight of the total weight of all components of the foamable composition, such as from about 1.5% to about 7.5% by weight of the total weight of all components of the foamable composition, such as from about 2% to about 7% by weight, such as from about 2.5% to about 6.5% by weight, such as from about 3% to about 6% by weight, such as from about 3.5% to about 5.5% by weight, such as from about 4% to about 5% by weight, for example about 4.5% by weight.

[0021] In certain exemplary embodiments, the HFO comprises from about 0.004 mol / 100 g to about 0.140 mol / 100 g of the matrix polymer, such as from about 0.007 mol / 100 g to about 0.125 mol / 100 g, for example, from about 0.009 mol / 100 g to about 0.120 mol / 100 g, for example, from about 0.010 mol / 100 g to about 0.108 mol / 100 g, for example, from about 0.015 mol / 100 g to about 0.0999 mol / 100 g, for example, from about 0.017 mol / 100 g to about 0.091 mol / 100 g, for example, from about 0.019 mol / 100 g to about 0.085 mol / 100 g, for example, from about 0.020 to about 0.075 mol / 100 g of the matrix polymer. In some exemplary embodiments, the HFO blowing agent comprises less than 0.05 moles / 100 grams of matrix polymer, e.g., less than 0.045 moles / 100 grams, less than about 0.03 moles / 100 grams, less than 0.025 moles / 100 grams, less than 0.023 moles / 100 grams, and 0.021 moles / 100 grams of matrix polymer.

[0022] In certain exemplary embodiments, the branched hydrocarbon co-blowing agent comprises from about 0.05% to about 6% by weight of the total weight of all components of the foamable composition, such as from about 0.1% to about 5.5% by weight, such as from about 0.5% to about 5% by weight, such as from about 0.8% to about 4.5% by weight, such as from about 0.9% to about 4% by weight, e.g., about 1.0% by weight of the total weight of all components. In certain exemplary embodiments, the branched hydrocarbon co-blowing agent comprises from about 0.0005 mol / 100g to about 0.150 mol / 100g of matrix polymer, such as from about 0.0010 mol / 100g to about 0.10 mol / 100g, such as from about 0.0050 mol / 100g to about 0.085 mol / 100g, such as from about 0.0080 mol / 100g to about 0.078 mol / 100g, such as from about 0.009 mol / 100g to about 0.065 mol / 100g, such as from about 0.0100 mol to about 0.020 mol / 100g of matrix polymer. In certain exemplary embodiments, the one or more second co-blowing agents comprise from about 0.05% to about 6% by weight of the total weight of all components of the foamable composition, such as from about 0.1% to about 5.5% by weight, such as from about 0.5% to about 5% by weight, such as from about 0.8% to about 4.5% by weight, such as from about 0.9% to about 4% by weight, e.g., about 1.0% by weight of the total weight of all components.

[0023] matrix polymer The matrix polymer forms the bulk of the foamable polymer mixture and provides strength, flexibility, toughness, and durability to the final product. The matrix polymer is not particularly limited, but generally, any foamable polymer may be used as the matrix polymer of the foamable polymer mixture. The matrix polymer may be a thermoplastic or thermosetting polymer. In some embodiments, the matrix polymer may comprise a single polymer. In some embodiments, the matrix polymer may comprise a blend of two or more polymers. In some embodiments, the matrix polymer may be selected to provide sufficient mechanical strength to the final polymer foam product. In some embodiments, the matrix polymer may be selected to be compatible with the process utilized to form the final polymer foam product. In some embodiments, the matrix polymer is chemically stable, i.e., generally non-reactive, within the expected temperature range the matrix polymer will experience during formation and subsequent use in the polymer foam. The matrix polymer may be present in the foamable polymer mixture in an amount of at least about 50% by weight (based on the total weight of all components excluding the blowing agent composition), from about 60% to about 100% by weight, from about 70% to about 99% by weight, from about 75% to about 98% by weight, from about 80% to about 96% by weight, or from about 85% to about 95% by weight. In certain exemplary embodiments, the matrix polymer may be present in an amount of from about 80% to about 100% by weight.

[0024] Non-limiting examples of suitable matrix polymers include alkenyl aromatic polymers, styrenic polymers, polystyrene (PS), styrenic copolymers, styrenic block copolymers, copolymers of styrene and butadiene, styrene acrylonitrile (SAN), acrylonitrile butadiene styrene, acrylic / styrene / acrylonitrile block terpolymers (ASA), styrene maleic anhydride copolymer (SMA), styrene methyl methacrylate copolymer (SMMA), polyolefins, polyethylene (PE), polypropylene (PP), ethylene and Included are copolymers of propylene, copolymers of vinyl acetate and ethylene, polyvinyl chloride (PVC), chlorinated polyvinyl chloride (CPVC), polycarbonate, polyisocyanurate, polyester, polyethylene terephthalate (PET), polyacrylate, polymethyl methacrylate (PMMA), polyphenylene oxide, polyurethane, phenolics, polysulfone, polyphenylene sulfide, acetal resins, polyamide, polyaramid, polyimide, polyetherimide, rubber modified polymers, thermoplastic polymer blends and combinations thereof.

[0025] In some exemplary embodiments, the matrix polymer is an alkenyl aromatic polymer material. Suitable alkenyl aromatic polymer materials include alkenyl aromatic homopolymers and copolymers of ethylenically unsaturated comonomers copolymerizable with alkenyl aromatic compounds. In addition, the alkenyl aromatic polymer material may contain a small proportion of non-alkenyl aromatic polymers. The alkenyl aromatic polymer material may be formed from one or more alkenyl aromatic homopolymers, one or more alkenyl aromatic copolymers, one or more blends of alkenyl aromatic homopolymers and copolymers, or blends thereof with non-alkenyl aromatic polymers. Examples of alkenyl aromatic polymers include, but are not limited to, alkenyl aromatic polymers derived from alkenyl aromatic compounds such as styrene, styrene acrylonitrile (SAN) copolymer, alpha-methylstyrene, ethylstyrene, vinylbenzene, vinyltoluene, chlorostyrene, and bromostyrene. In at least one embodiment, the alkenyl aromatic polymer comprises polystyrene (PS).

[0026] In certain exemplary embodiments, minor amounts of monoethylenically unsaturated monomers, such as C2-C6 alkyl acids and esters, ionomeric derivatives, and C4-C8 dienes, may be copolymerized with alkenyl aromatic monomers to form alkenyl aromatic polymers. Non-limiting examples of copolymerizable monomers include acrylic acid, methacrylic acid, ethacrylic acid, maleic acid, itaconic acid, acrylonitrile, maleic anhydride, methyl acrylate, ethyl acrylate, isobutyl acrylate, n-butyl acrylate, methyl methacrylate, vinyl acetate, and butadiene. In certain exemplary embodiments, the matrix polymer may be formed solely from polystyrene. In certain exemplary embodiments, the matrix polymer may be formed substantially from (e.g., greater than 95% by weight) polystyrene. In certain exemplary embodiments, the matrix polymer may be formed from about 40 to 100% by weight of polystyrene, for example, about 45 to 99% by weight, for example, about 50 to 98% by weight, for example, about 55 to 97% by weight, for example, about 60 to 96% by weight, for example, about 65 to 95% by weight, for example, about 70 to 94% by weight, for example, about 75 to 93% by weight, for example, about 80 to 92% by weight, for example, about 85 to 91% by weight, for example, about 80 to 90% by weight of polystyrene. In certain exemplary embodiments, the polymer foam may include at least one optional additive, including, but not limited to, antioxidants, heat stabilizers, UV stabilizers, acid scavengers, flame retardant compositions, synergists, nucleating agents, plasticizers, pigments, elastomers, processing agents, extrusion aids, fillers, antistatic agents, biocides, termiticides, colorants, oils, or waxes. In certain exemplary embodiments, the polymer foam may include a mixture of additives. These optional additives may be included in amounts necessary to obtain the desired properties of the foamable polymer mixture or the resulting polymer foam. The additives may be added to the foamable polymer mixture or incorporated before, during, or after the polymerization process used to create the matrix polymer.

[0027] In certain exemplary embodiments, the polymeric foam includes one or more processing aids, such as a carbonate composition. Exemplary carbonate compositions include propylene carbonate, dimethyl carbonate, butylene carbonate, ethylene carbonate, and the like. The one or more processing aids may be included in the polymeric foam material in an amount of 0 to 20% by weight, e.g., about 0.05 to about 17% by weight, about 0.1 to about 15% by weight, about 1.0 to about 10% by weight, about 1.5 to about 8% by weight, and about 2 to about 5% by weight.

[0028] Manufacturing method The polymer foams containing the blowing agent composition may be extruded or expanded foams and may be made by modifying known manufacturing methods using conventional manufacturing equipment. In some embodiments, the polymer foam of the present disclosure is an extruded polymer foam produced by an extrusion process. The extrusion apparatus may include a single-screw or twin-screw extruder including a barrel having a spiral flight thereon and surrounding a screw configured to compress and thereby heat and melt the material introduced into the screw extruder. The matrix polymer and optional additives form a matrix polymer mixture, which may be fed to the screw extruder from one or more feed hoppers as a flowable solid, such as beads, granules, or pellets, or as a liquid or semi-liquid melt. As the matrix polymer mixture progresses through the screw extruder, the increasingly narrowing spacing of the flights defines successively smaller spaces through which the matrix polymer mixture is forced by the rotation of the screw. This decreasing volume acts to increase the pressure of the matrix polymer mixture to obtain a polymer melt (if a solid starting material is used) and / or to increase the pressure of the polymer melt.

[0029] Ports may be provided through the barrel configured to inject one or more additives into the matrix polymer mixture as it progresses through the screw extruder. In some embodiments, additives such as processing aids, nucleating agents, flame retardants, antioxidants, or stabilizers may also be introduced into the polymer mixture through ports. Similarly, one or more additional ports may be provided through the barrel for injecting one or more blowing agent compositions into the polymer mixture. In some embodiments, one or more optional additives and the blowing agent composition are introduced through a single port. In some embodiments, the optional additives and the blowing agent composition are introduced through multiple ports. Once these additives and the blowing agent composition are introduced into the matrix polymer mixture, the resulting mixture is subjected to several additional blends sufficient to ensure that each of the additives is uniformly distributed throughout the polymer mixture, resulting in an extruded composition.

[0030] The extruded composition is then passed through an extrusion die and exits the die into a region of reduced pressure (which may be below atmospheric pressure), which causes the blowing agent composition to expand and produce a polymeric foam material. This reduced pressure may be achieved gradually as the extruded composition passes through successively larger openings in the die, or through some device downstream of the extrusion die suitable for providing some control over the manner in which the pressure on the extruded composition is reduced. The extruded, expanded polymeric foam material may be subjected to further processing, such as calendaring, flooding, cooling sprays, or other operations to control the thickness and other properties of the resulting polymeric foam material. In some embodiments, the polymer foams of the present disclosure are extruded polymer beads made by a bead extrusion method. Bead extrusion is similar to the extrusion process described above. However, in bead extrusion, the extrusion die contains multiple small holes so that the extrusion composition is extruded as beads. These beads typically range in diameter from about 0.05 mm to about 2.0 mm. Furthermore, the extrusion composition cannot expand once the beads containing the extrusion composition exit the extrusion die. Instead, the beads containing the extrusion composition are discharged into a cooling chamber or bath where the beads are cooled to the glass transition temperature (T g ) This rapid cooling prevents foaming of the extruded composition within the beads.

[0031] In some embodiments of bead extrusion, the matrix polymer, blowing agent composition, and optional additives are introduced into an extruder as described above to form the extruded composition. In some embodiments of bead extrusion, the matrix polymer and optional additives are introduced into an extruder as described above to form the extruded composition, but the blowing agent composition is added to the extruded beads via a pressure vessel after the beads have been extruded and cooled. In some embodiments, the polymer foams of the present disclosure are expanded polymer foams made by emulsion or suspension polymerization methods. In some embodiments of expanded polymer foams, the matrix polymer is polymerized from monomers dispersed in a liquid phase in a reaction vessel. In some embodiments, the blowing agent composition is added to the polymer mixture by adding the blowing agent as a diluent for the liquid phase in the reaction vessel during the polymerization reaction. In some embodiments, the blowing agent composition is used as a liquid phase in the reaction vessel during the polymerization reaction. In some embodiments, the blowing agent composition is added to the polymer mixture in a pressure vessel after completion of the polymerization reaction. The extruded composition is then forced through an extrusion die and exits the die into a region of reduced pressure (which may be below atmospheric pressure), which causes the blowing agent to expand and produce a polymeric foam layer or slab. The polymeric foam may be subjected to further processing such as calendaring, flooding, cooling spraying, or other operations to control the thickness and other properties of the resulting polymeric foam product.

[0032] polymer foam The manufacturing method produces a polymer foam. In some exemplary embodiments, the manufacturing method of a foamable polymer mixture produces a rigid, substantially closed-cell polymer foam board prepared by an extrusion process. The extruded foam has a cellular structure in which the cells are defined by cell membranes and struts. The struts form at the intersections of the cell membranes, and the cell membranes cover the interconnecting cell windows between the struts. In some exemplary embodiments, the foam has an average density of less than 5 pounds per cubic foot ("pcf"), or less than 4 pcf, or less than 3 pcf. In some exemplary embodiments, the polymer foam has a density of from about 1 pcf to about 4.5 pcf, such as from about 1.2 pcf to about 4 pcf, for example, from about 1.3 pcf to about 3.5 pcf, for example, from about 1.4 pcf to about 3 pcf, for example, from about 1.5 pcf to about 2.8 pcf, for example, from about 1.6 pcf to about 2.6 pcf, for example, from about 1.7 pcf to about 2.5 pcf, for example, from about 1.8 pcf to about 2.4 pcf, for example, from about 1.9 pcf to about 2.3 pcf, for example, from about 2.0 pcf to about 2.2 pcf. In some exemplary embodiments, the polymer foam has a density of about 2.0 pcf or less.

[0033] It should be understood that the phrase "substantially closed-cell" is intended to indicate that the foam contains all closed cells, or that nearly all of the cells within the cell structure are closed. In some embodiments, 20% or less of the cells are open, particularly 10% or less, or 5% or less are open or otherwise "non-closed." In some embodiments, about 0.5% to about 4.0% of the cells are open, e.g., about 0.75% to about 3.5%, e.g., about 1.0% to about 3.2%, e.g., about 1.2% to about 3.0%, e.g., about 1.5% to about 2.8%, e.g., about 1.75% to about 2.5%, e.g., about 2.0% to about 2.25% of the cells are open. A closed-cell structure serves to increase the R-value of the resulting foam insulation product. However, it should be understood that it is within the scope of the present invention to produce an open-cell structure.

[0034] The average cell size of the matrix polymer cells in the foams and foamed products of the present invention may be from about 0.05 mm (50 μm) to about 0.4 mm (400 μm), for example, from about 0.1 mm (100 μm) to about 0.3 mm (300 μm), for example, from about 0.11 mm (110 μm) to about 0.25 mm (250 μm), for example, from about 0.12 mm (120 μm) to about 0.2 mm (200 μm), for example, from about 0.13 mm (130 μm) to about 0.18 mm (180 μm), for example, from about 0.14 mm (140 μm) to about 0.16 mm (160 μm). The foams of the present invention may be formed into insulation products such as rigid insulation board, insulating foam, packaging products, and building or underground insulation (e.g., highway, airport runway, railroad, and underground utility insulation). Additionally, the foamable polymer blends of the present invention may produce polymer foams having high compressive strength, which defines the ability of a foam material to withstand axial compression forces. In some embodiments, the foam compositions of the present invention have compressive strengths within a desirable range for polymer foams, from about 6 psi to about 120 psi. In some embodiments, the foamable polymer blends of the present invention produce foams having compressive strengths of from about 10 psi to about 110 psi, e.g., from about 20 psi to about 100 psi, e.g., from about 25 psi to about 90 psi, e.g., from about 30 psi to about 80 psi, e.g., from about 35 psi to about 70 psi, e.g., from about 40 psi to about 60 psi, e.g., from about 45 psi to about 50 psi.

[0035] Furthermore, the foamable polymer mixture of the present invention may produce polymer foams with a high level of dimensional stability. For example, the change in dimension in any direction is 5% or less, such as 3% or less, 2% or less, and 1.5% or less. As used herein, average cell size is the average of cell sizes determined in the X, Y, and Z directions. Specifically, the "X" direction is the extrusion direction, the "Y" direction is the cross-machine direction, and the "Z" direction is the thickness. In the present invention, the greatest impact on cell expansion is in the X and Y directions, which is desirable from the perspective of orientation and R-value. In addition, with further process modifications, it is possible to increase Z orientation and improve mechanical properties while still achieving acceptable thermal properties. The polymer foam of the present invention can be used to make insulation products such as rigid insulation boards, insulation foams, and packaging products.

[0036] Additionally, the foam compositions of the present invention produce polymeric foams having an insulation value (R-value) per inch of at least 4, or from about 4 to about 7. R-value, or total thermal resistance, is a measure of resistance to heat transfer. A method for determining R-value is described below. Thermal conductivity, k, is defined as the ratio of heat flow per unit cross-sectional area to the temperature drop per unit thickness, and is given in US units as: Btu·in k=----------------------------------------------------------------- hr·ft 2 °F and in meters: W k=--------------------------------- m·K Heat transfer through insulating materials can occur by solid conduction, gas conduction, radiation, and convection. The total thermal resistance (R-value), R, is a measure of resistance to heat transfer, R=t / k where t = thickness.

[0037] The thermal conductivity k of the foam of the present invention after aging for 7 days is about 0.16 to about 0.18 Btu in / hr ft 2 °F, for example about 0.162 to about 0.178, for example about 0.164 to about 0.176, for example about 0.166 to about 0.174, for example about 0.168 to about 0.172, for example about 0.170 Btu in / hr ft 2 The thermal conductivity k of the foams of the present invention after aging for 60 days is about 0.17 to about 0.185 Btu in / hr ft 2 °F, for example about 0.172 to about 0.184, for example about 0.174 to about 0.182, for example about 0.175 to about 0.181, for example about 0.176 to about 0.180, for example about 0.178 Btu in / hr ft 2 ·°F. [Example]

[0038] Example 1 A series of experiments were conducted to form 1.0 inch extruded polystyrene (XPS) foam samples using various hydrocarbons as co-blowing agents with HFO-1234ze. The hydrocarbon co-blowing agents tested included n-butane, isobutane, n-pentane, isopentane, and cyclopentane. For each foam sample, the formulation contained 98.5 wt.% polystyrene, 1 wt.% flame retardant, 0.5 wt.% infrared attenuating agent, and 7.8 wt.% blowing agent composition. The amount of each blowing agent component is given as a wt.% of the total composition and in moles per 100 g of matrix polymer. The formulation and physical properties of the blowing agent composition for each test sample are shown in Tables 1-5 below.

[0039] [Table 1]

[0040] [Table 2]

[0041] [Table 3]

[0042] [Table 4]

[0043] [Table 5] A graph of the thermal insulation (k-factor after 7 days) for each foam formulation is shown in Figure 1. For each formulation, the thermal insulation remained relatively constant as the amount of HFO was varied. There appears to be no direct benefit to increasing the weight percent of HFO blowing agent (an expensive material) relative to the hydrocarbon co-blowing agent in as-produced polymer foams.

[0044] Example 2 The foam formulations of Example 1 were analyzed for thermal insulation as the samples aged. The thermal aging curves for C1-C6 (foam formulations containing n-pentane as a co-blowing agent) are shown in Figure 2. The thermal aging curves for the other foam formulations of Example 1 followed the same general trend, as shown in Figure 2. As HFO / n-pentane foams age, the foam sample with the highest HFO concentration (Sample C-1) exhibits slightly better insulation than the foam samples with lower HFO concentrations (Samples C-2 through C-6). However, it should be noted that although Sample C-1 has approximately 30% more HFO than Sample C-6 (7.55 wt% vs. 5.80 wt%), the k-factor of C-1 at 60 days is only about 2% higher than that of C-6 (0.181 vs. 0.185). Increasing the mass percentage of HFO blowing agent (an expensive material) relative to the hydrocarbon co-blowing agent does not appear to offer significant long-term benefits as polymer foams age.

[0045] Example 3 The foam formulations of Example 1 (i.e., Samples A-6, B-6, C-6, D-6, and E-6) containing 5.8 wt.% HFO and 2.0 wt.% hydrocarbon were compared for their insulating properties with aging. As a comparative example, similar foams containing 5.80 wt.% HFO-1234ze and 2.00 wt.% HFC-152 were also evaluated for their insulating properties with aging. The thermal aging curves for these samples are shown in Figure 3. The foam sample containing HFO and isobutane (sample B-6) showed the best thermal insulation, with a k-factor of approximately 0.180 Btu in / h ft after 60 days. 2 The foam sample containing HFO and isopentane (sample D-6) showed the next best insulation performance, with a k-factor of approximately 0.183 Btu in / h ft after 60 days. 2 ·°F. Foam samples containing n-butane, n-pentane, and cyclopentane (samples A-6, C-6, and E-6, respectively) exhibited comparable insulating properties, with k-factors of approximately 0.184–0.185 Btu·in / h·ft after 60 days. 2 The comparative sample containing HFO and HFC (sample COMP) exhibited the poorest insulation, with a k-factor of approximately 0.188 Btu in / h ft after 60 days. 2 The average temperature was 100°F. These results suggest that polymer foams using blowing agents containing HFOs and branched hydrocarbons such as isobutane or isopentane exhibit superior thermal insulation properties to similar foams using blowing agents containing HFOs and linear or cyclic hydrocarbons such as n-butane, n-pentane, or cyclopentane. Furthermore, polymer foams using blowing agents containing HFOs and branched hydrocarbons such as isobutane or isopentane also exhibit superior thermal insulation properties to similar foams using blowing agents containing HFOs and HFCs but without branched hydrocarbons.

[0046] Example 4 The data for Example 3, presented in Figure 3, were normalized to compare the hydrocarbon co-blowing agent on a molar basis (2.88 moles / 100 g of matrix polymer) rather than a mass basis (2.0 wt%) of each composition. The normalized thermal aging curves are shown in Figure 4. When normalized in this manner, foams containing isopentane, isobutane, and n-butane (Samples D-6, B-6, and A-6, respectively) exhibit superior thermal insulation compared to foams containing n-pentane and cyclopentane (Samples C-6 and E-6, respectively). The comparative sample (Sample COMP) again exhibits the poorest thermal insulation.

[0047] Example 5 A series of experiments was conducted to produce the lowest possible density extruded polystyrene (XPS) foam specimens using 3.00 wt% HFO-1234ze blowing agent and 4.80 wt% various hydrocarbon co-blowing agents. The hydrocarbon co-blowing agents tested included n-butane, isobutane, n-pentane, isopentane, and cyclopentane. The specimen thickness was held constant at 1.00 inches. A 1.0-inch board has an R-value of 5, or a thermal conductivity of 0.20 Btu·in / ft 2 The R-value is the inverse of thermal conductivity. The lower the thermal conductivity, the higher the R-value. As a comparative example, a similar foam containing 3.00 wt.% HFO-1234ze and 4.80 wt.% HFC-152a was also evaluated for its thermal insulation properties with aging. For each foam sample, the formulation included 98.5 wt.% polystyrene, 1 wt.% flame retardant, 0.5 wt.% infrared attenuating agent, and 7.8 wt.% blowing agent composition. The blowing agent composition formulation for each series of test samples is shown in Table 6 below. [Table 6]

[0048] Figure 5 shows a graph of the heat aging curves of foams of various densities using 3.00 wt% HFO blowing agent and 4.80 wt% isobutane. Each foam contained less than 0.03 moles of HFO-1234ze. 2.52 lb / ft 3The foam sample with a density of 1.0001 exhibited the highest thermal resistance, with a k-factor of approximately 0.179 Btu in / h ft after 180 days. 2 However, lower density foams also exhibited acceptable thermal resistance values, with k-factors ranging from 2.25 to 1.43 lb / ft after 180 days. 3 and foams with densities of approximately 0.180 to 0.194 Btu in / h ft, respectively. 2 As mentioned above, for a 1.0-inch board, an R-value of 5 has a thermal conductivity of 0.20 Btu in / ft 2 ·h·°F. Thus, each foam sample achieved an R-value of at least 5. Figure 6 shows a graph comparing foams of various densities and containing various hydrocarbon co-blowing agents. For all foam densities, samples F-2 and F-4, containing isobutane and isopentane as co-blowing agents, respectively, show better heat resistance (lower k-factor) after 7 days than samples F-1 and F-3, containing n-butane and n-pentane, respectively. 3 The dotted line at density 1.75 lb / ft represents the target density for most commercially available foams. 3 Substantially lower foam products show that acceptable heat resistance can be achieved when using isobutane or isopentane as a co-blowing agent and an HFO as the blowing agent.

[0049] Example 6 A series of experiments were conducted to form extruded polystyrene (XPS) foam samples using various concentrations of HFO-1234ze, isobutane, and carbon dioxide. The target foam density was 2.25 + / - 0.05 lb / ft. 3The total blowing agent was maintained at 7.8 wt% of the foamable material using CO2, while the concentrations of HFO-1234ze and isobutane were varied. The ratio of HFO to isobutane was kept constant at 1.6. For each foam sample, the formulation contained 98.5 wt% polystyrene, 1 wt% flame retardant, 0.5 wt% infrared attenuating agent, and 7.8 wt% blowing agent composition. The amount of each blowing agent component is given as the wt% of the total composition and in moles per 100 g of matrix polymer. The blowing agent composition formulation, foam density, and 7-day k-factor for each sample are shown in Table 7 below.

[0050] [Table 7]

[0051] Thermal aging curves for foams containing various concentrations of HFO-1234ze, isobutane, and carbon dioxide are shown in Figure 7. The curves show that the thermal conductivity of the foam increases as the concentrations of HFO-1234ze and isobutane decrease and are replaced by carbon dioxide. Although the present invention has been described with reference to a particular polystyrene foam material, the method of the present invention is applicable to various combinations of other polymer compositions and blending agents to obtain a variety of polymer foam materials. Although exemplary embodiments of the present invention have been disclosed herein and specific terms have been employed, they are used and interpreted in a generic and descriptive sense only and not for purposes of limitation. Thus, those skilled in the art will recognize that various changes in form and detail may be made in the disclosed apparatus and methods without departing from the spirit and scope of the present invention, as set forth in the following claims.

Claims

1. a) a hydrofluoroolefin (HFO) blowing agent, and b) Branched Hydrocarbon Co-Blowing Agent 1. A blowing agent composition for polymer foams, comprising:

2. The HFO blowing agent is selected from the group consisting of 3,3,3-trifluoropropene (HFO-1243zf), 2,3,3-trifluoropropene, (cis and / or trans)-1,3,3,3-tetrafluoropropene (HFO-1234ze), 1,1,3,3-tetrafluoropropene, 2,3,3,3-tetrafluoropropene (HFO-1234yf), (cis and / or trans)-1,2,3,3,3-pentafluoropropene (HFO-1225ye), 1,1,3,3,3-pentafluoropropene (HFO-1225zc), 1,1,2,3,3-pentafluoropropene (HFO-1225yf), 1,1,2,3,3-pentafluoropropene (HFO-1225ye), 1,1,3,3,3-pentafluoropropene (HFO-1225yf), 1,1,2 ... hexafluoropropene (HFO-1216), 2-fluoropropene, 1-fluoropropene, 1,1-difluoropropene, 3,3-difluoropropene, 4,4,4-trifluoro-1-butene, 2,4,4,4-tetrafluoro-1-butene, 3,4,4,4-tetrafluoro-1-butene, octafluoro-2-pentene (HFO-1438), 1,1,3,3,3-pentafluoro-2-methyl-1-propene, octafluoro-1-butene, 2,3,3,4,4,4-hexafluoro-1-butene 1,1,1,4,4,4-hexafluoro-2-butene (HFO-1336 m / z), 1,2-difluoroethene (HFO-1132), 1,1,1,2,4,4,4-heptafluoro-2-butene, 3-fluoropropene, 2,3-difluoropropene, 1,1,3-trifluoropropene, 1,3,3-trifluoropropene, 1,1,2-trifluoropropene, 1-fluorobutene, 2-fluorobutene, 2-fluoro-2-butene, 1,1-difluoro-1-butene, 3,3-difluoro-1-butene, 3,4,4-trifluoro-1-butene 1-butene, 2,3,3-trifluoro-1-butene, 1,1,3,3-tetrafluoro-1-butene, 1,4,4,4-tetrafluoro-1-butene, 3,3,4,4-tetrafluoro-1-butene, 4,4-difluoro-1-butene, 1,1,1-trifluoro-2-butene, 2,4,4,4-tetrafluoro-1-butene, 1,1,1,2-tetrafluoro-2-butene, 1,1,4,4,4-pentafluoro-1-butene, 2,3,3,4,4-pentafluoro-1-butene, 1,2,3,3,4,4,4-heptafluoro-1-butene, 1,1,2,3,The blowing agent composition of claim 1, wherein the blowing agent is selected from the group consisting of 4,4,4-heptafluoro-1-butene, 1,3,3,3-tetrafluoro-2-(trifluoromethyl)-propene, and combinations thereof.

3. 2. The blowing agent composition of claim 1, wherein the branched hydrocarbon co-blowing agent is selected from the group consisting of isobutane, isopentane, neopentane, isohexane, 3-methylpentane, 2,3-dimethylbutane, neohexane, isoheptane, 3-methylhexane, 2,2-dimethylpentane, 2,3-dimethylpentane, 2,4-dimethylpentane, 3,3-dimethylpentane, 3-ethylpentane, 2,2,3-trimethylbutane, and combinations thereof.

4. 10. The blowing agent composition of claim 1, wherein the HFO blowing agent comprises from about 14% to about 89% by weight of the total weight of the blowing agent composition.

5. 10. The blowing agent composition of claim 1, wherein the branched hydrocarbon co-blowing agent comprises from about 11 wt.% to about 86 wt.% of the total weight of the blowing agent composition.

6. 10. The blowing agent composition of claim 1, further comprising one or more second co-blowing agents selected from the group consisting of hydrofluorocarbons ("HFCs"), hydrochlorofluorocarbons ("HCFOs"), carbon dioxide, and water.

7. 7. The blowing agent composition of claim 6, wherein the one or more second co-blowing agents are present in an amount from about 0.5 wt.% to about 50 wt.%, based on the total weight of the blowing agent composition.

8. The blowing agent composition of claim 1 used in a foamable polymer composition.

9. 10. The blowing agent composition of claim 8, wherein the foamable polymer composition comprises a matrix polymer selected from the group consisting of alkenyl aromatic polymers, styrenic polymers, styrenic copolymers, styrenic block copolymers, polyolefins, halogenated vinyl polymers, polycarbonates, polyisocyanurates, polyesters, polyacrylates, polyurethanes, phenolics, polysulfones, polyphenylene sulfides, acetal resins, polyamides, polyaramids, polyimides, polyetherimides, rubber-modified polymers, thermoplastic polymer blends, and combinations thereof.

10. a) a matrix polymer composition, and b) A blowing agent composition comprising a hydrofluoroolefin (HFO) blowing agent and a branched hydrocarbon co-blowing agent. and wherein the foamable polymer composition is substantially free of water.

11. The HFO blowing agent is selected from the group consisting of 3,3,3-trifluoropropene (HFO-1243zf), 2,3,3-trifluoropropene, (cis and / or trans)-1,3,3,3-tetrafluoropropene (HFO-1234ze), 1,1,3,3-tetrafluoropropene, 2,3,3,3-tetrafluoropropene (HFO-1234yf), (cis and / or trans)-1,2,3,3,3-pentafluoropropene (HFO-1225ye), 1,1,3,3,3-pentafluoropropene (HFO-1225zc), 1,1,2,3,3-pentafluoropropene (HFO-1225yf), 1,1,2,3,3-pentafluoropropene (HFO-1225ye), 1,1,3,3,3-pentafluoropropene (HFO-1225yf), 1,1,2 ... hexafluoropropene (HFO-1216), 2-fluoropropene, 1-fluoropropene, 1,1-difluoropropene, 3,3-difluoropropene, 4,4,4-trifluoro-1-butene, 2,4,4,4-tetrafluoro-1-butene, 3,4,4,4-tetrafluoro-1-butene, octafluoro-2-pentene (HFO-1438), 1,1,3,3,3-pentafluoro-2-methyl-1-propene, octafluoro-1-butene, 2,3,3,4,4,4-hexafluoro-1-butene 1,1,1,4,4,4-hexafluoro-2-butene (HFO-1336 m / z), 1,2-difluoroethene (HFO-1132), 1,1,1,2,4,4,4-heptafluoro-2-butene, 3-fluoropropene, 2,3-difluoropropene, 1,1,3-trifluoropropene, 1,3,3-trifluoropropene, 1,1,2-trifluoropropene, 1-fluorobutene, 2-fluorobutene, 2-fluoro-2-butene, 1,1-difluoro-1-butene, 3,3-difluoro-1-butene, 3,4,4-trifluoro-1-butene 1-butene, 2,3,3-trifluoro-1-butene, 1,1,3,3-tetrafluoro-1-butene, 1,4,4,4-tetrafluoro-1-butene, 3,3,4,4-tetrafluoro-1-butene, 4,4-difluoro-1-butene, 1,1,1-trifluoro-2-butene, 2,4,4,4-tetrafluoro-1-butene, 1,1,1,2-tetrafluoro-2-butene, 1,1,4,4,4-pentafluoro-1-butene, 2,3,3,4,4-pentafluoro-1-butene, 1,2,3,3,4,4,4-heptafluoro-1-butene, 1,1,2,3,The expandable polymer composition of claim 10, wherein the expandable polymer composition is selected from the group consisting of 4,4,4-heptafluoro-1-butene, 1,3,3,3-tetrafluoro-2-(trifluoromethyl)-propene, and combinations thereof.

12. 11. The expandable polymer composition of claim 10, wherein the branched hydrocarbon co-blowing agent is selected from the group consisting of isobutane, isopentane, neopentane, isohexane, 3-methylpentane, 2,3-dimethylbutane, neohexane, isoheptane, 3-methylhexane, 2,2-dimethylpentane, 2,3-dimethylpentane, 2,4-dimethylpentane, 3,3-dimethylpentane, 3-ethylpentane, 2,2,3-trimethylbutane, and combinations thereof.

13. 11. The expandable polymer composition of claim 10, wherein the HFO blowing agent comprises from about 1% to about 8% by weight of the total weight of the expandable polymer composition.

14. 11. The foamable polymer composition of claim 10, wherein the branched hydrocarbon co-blowing agent comprises from about 1% to about 6% by weight of the total weight of the foamable polymer composition.

15. 11. The expandable polymer composition of claim 10, wherein the HFO blowing agent comprises less than 0.03 moles / 100 grams of matrix polymer.

16. 11. The expandable polymer composition of claim 10, wherein the matrix polymer is selected from the group consisting of alkenyl aromatic polymers, styrenic polymers, styrenic copolymers, styrenic block copolymers, polyolefins, halogenated vinyl polymers, polycarbonates, polyisocyanurates, polyesters, polyacrylates, polyurethanes, phenolics, polysulfones, polyphenylene sulfides, acetal resins, polyamides, polyaramids, polyimides, polyetherimides, rubber-modified polymers, thermoplastic polymer blends, and combinations thereof.

17. 1. A method for producing a polymer foam, comprising: a) providing a matrix polymer composition; b) melting the matrix polymer composition in an extruder; c) injecting a blowing agent composition comprising a hydrofluoroolefin (HFO) blowing agent and a branched hydrocarbon co-blowing agent into the molten matrix polymer composition in the extruder to form a foamable polymer composition, wherein the foamable polymer composition is substantially free of water and carbon dioxide; and d) extruding the foamable polymer composition to form a polymer foam. A method comprising:

18. The HFO blowing agent is selected from the group consisting of 3,3,3-trifluoropropene (HFO-1243zf), 2,3,3-trifluoropropene, (cis and / or trans)-1,3,3,3-tetrafluoropropene (HFO-1234ze), 1,1,3,3-tetrafluoropropene, 2,3,3,3-tetrafluoropropene (HFO-1234yf), (cis and / or trans)-1,2,3,3,3-pentafluoropropene (HFO-1225ye), 1,1,3,3,3-pentafluoropropene (HFO-1225zc), 1,1,2,3,3-pentafluoropropene (HFO-1225yf), 1,1,2,3,3-pentafluoropropene (HFO-1225ye), 1,1,3,3,3-pentafluoropropene (HFO-1225yf), 1,1,2 ... hexafluoropropene (HFO-1216), 2-fluoropropene, 1-fluoropropene, 1,1-difluoropropene, 3,3-difluoropropene, 4,4,4-trifluoro-1-butene, 2,4,4,4-tetrafluoro-1-butene, 3,4,4,4-tetrafluoro-1-butene, octafluoro-2-pentene (HFO-1438), 1,1,3,3,3-pentafluoro-2-methyl-1-propene, octafluoro-1-butene, 2,3,3,4,4,4-hexafluoro-1-butene 1,1,1,4,4,4-hexafluoro-2-butene (HFO-1336 m / z), 1,2-difluoroethene (HFO-1132), 1,1,1,2,4,4,4-heptafluoro-2-butene, 3-fluoropropene, 2,3-difluoropropene, 1,1,3-trifluoropropene, 1,3,3-trifluoropropene, 1,1,2-trifluoropropene, 1-fluorobutene, 2-fluorobutene, 2-fluoro-2-butene, 1,1-difluoro-1-butene, 3,3-difluoro-1-butene, 3,4,4-trifluoro-1-butene 1-butene, 2,3,3-trifluoro-1-butene, 1,1,3,3-tetrafluoro-1-butene, 1,4,4,4-tetrafluoro-1-butene, 3,3,4,4-tetrafluoro-1-butene, 4,4-difluoro-1-butene, 1,1,1-trifluoro-2-butene, 2,4,4,4-tetrafluoro-1-butene, 1,1,1,2-tetrafluoro-2-butene, 1,1,4,4,4-pentafluoro-1-butene, 2,3,3,4,4-pentafluoro-1-butene, 1,2,3,3,4,4,4-heptafluoro-1-butene, 1,1,2,3,The method of claim 17, wherein the fluorocarbon is selected from the group consisting of 4,4,4-heptafluoro-1-butene, 1,3,3,3-tetrafluoro-2-(trifluoromethyl)-propene, and combinations thereof.

19. 18. The method of claim 17, wherein the branched hydrocarbon co-blowing agent is selected from the group consisting of isobutane, isopentane, neopentane, isohexane, 3-methylpentane, 2,3-dimethylbutane, neohexane, isoheptane, 3-methylhexane, 2,2-dimethylpentane, 2,3-dimethylpentane, 2,4-dimethylpentane, 3,3-dimethylpentane, 3-ethylpentane, 2,2,3-trimethylbutane, and combinations thereof.

20. 18. The method of claim 17, wherein the HFO blowing agent comprises from about 1% to about 8% by weight of the total weight of the foamable polymer composition.

21. 18. The method of claim 17, wherein the branched hydrocarbon co-blowing agent comprises from about 1% to about 6% by weight of the total weight of the foamable polymer composition.

22. 18. The method of claim 17, wherein the matrix polymer is selected from the group consisting of alkenyl aromatic polymers, styrenic polymers, styrenic copolymers, styrenic block copolymers, polyolefins, vinyl halide polymers, polycarbonates, polyisocyanurates, polyesters, polyacrylates, polyurethanes, phenolics, polysulfones, polyphenylene sulfides, acetal resins, polyamides, polyaramids, polyimides, polyetherimides, rubber modified polymers, thermoplastic polymer blends, and combinations thereof.

23. The method of claim 17, wherein the polymer foam has an R value of from about 4 to about 7.

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