Barrier coating composition for use in the manufacture of polymeric foam products - Patents.com

Abstract

The foamed polymeric insulation product includes a polymer foam formed from a foamable polymer composition comprising: a) a thermoplastic matrix polymer composition; and b) a blowing agent composition. A barrier coating is formed directly on at least one of the first major surface and the second major surface, the barrier coating being formed from a barrier coating composition comprising a dispersion of at least one polymer selected from polyvinylidene dichloride (PVDC), polyvinylidene fluoride (PVDF), polyvinyl chloride (PVC), polyvinyl alcohol, ethylene vinyl alcohol, polyurethane, styrene butadiene (SBR), and combinations or copolymers thereof, and a viscosity modifier.

Description

[Technical field]

[0001] (CROSS REFERENCE TO RELATED APPLICATIONS) This application claims the benefit of and priority to U.S. Provisional Patent Application No. 63 / 249,246, filed September 28, 2021, the entire contents of which are incorporated herein by reference.

[0002] FIELD OF THEINVENTION The present invention relates to a process for forming polymer foams, and in particular to the production of extruded thermoplastic foams. The present invention provides the use of a barrier coating to retain blowing agents and reduce blowing agent levels in thermoplastic polymer foams while maintaining desired foaming properties. [Background technology]

[0003] Polymer foams, such as extruded polymer foam or "XPS" foam, are generally produced by melting a polymer matrix composition to form a polymer melt and incorporating one or more blowing agents and other additives into the polymer melt under conditions that provide thorough mixing of the blowing agent and polymer while preventing the mixture from foaming prematurely, e.g., under pressure. The mixture is then typically extruded through a single or multistage extrusion die, cooled, and the pressure on the mixture is reduced to foam the mixture and produce a foamed product. As will be appreciated, the relative amounts of polymer, blowing agent, and additives; temperature; and the method of reducing pressure affect the quality of the resulting foam product. Also, as will be appreciated, the foamable mixture is maintained under relatively high pressure until it passes through the extrusion die, where it is expanded in a region of lower pressure.

[0004] The solubility of traditional blowing agents such as chlorofluorocarbons ("CFCs") and certain alkanes in polymer melts tends to reduce the melt viscosity and improve cooling of the expanded polymer melt. For example, combinations of pentane and CFCs such as Freon 11 or 12 are partially soluble in polystyrene and have been used to produce polystyrene foams that exhibit generally acceptable appearance and physical properties such as surface finish, cell size and distribution, orientation, shrinkage, thermal insulation properties (R-value), and stiffness.

[0005] However, in response to environmental concerns regarding the use of such CFC compounds, the widespread use of such compounds in applications such as aerosol propellants, refrigerants, blowing agents and specialty solvents, and their associated air emissions, has been dramatically reduced or eliminated in recent years through government regulations.

[0006] The shift away from the use of CFCs has led to the utilization of alternative blowing agents such as hydrogen-containing chlorofluoroalkanes (HCFCs). However, HCFCs still contain some chlorine and are therefore said to have ozone depletion potential (ODP).

[0007] Another class of blowing agents, the hydrofluorocarbons (HFCs), have been used as a more ozone-friendly option that offers desirable improvements such as zero ODP and a lower (but still potentially significant) global warming potential (GWP). However, these compounds are expensive, tend to have low solubility in polystyrene, and can still have a significant GWP. For example, HFC-134a has a GWP of 1430.

[0008] Hydrofluoroolefin (HFO) blowing agents, which are a type of fluorinated alkene, are considered to be more environmentally friendly than traditional halogenated blowing agents. For example, HFOs are considered to have reduced ODP and GWP compared to traditional fluorocarbon and hydrofluorocarbon blowing agents. However, these compounds tend to be expensive, and there is a need to minimize the amount of these compounds required to produce polymer foam products with desirable physical properties. Summary of the Invention

[0009] A general inventive concept relates to a foamed polymeric insulation product comprising a polymeric foam having a first major surface and a second major surface, and a barrier coating formed on at least one of the first major surface and the second major surface. The polymeric foam is formed from a foamable polymer composition comprising a thermoplastic matrix polymer composition and a blowing agent composition. The barrier coating is formed from a barrier coating composition comprising a dispersion of at least one polymer selected from the group consisting of polyvinylidene dichloride (PVDC), polyvinyl alcohol, ethylene vinyl alcohol, polyurethane, styrene butadiene (SBR), and combinations thereof. In some embodiments, the foamed polymeric insulation product has a thermal resistance value (R-value) of at least 4.75 / inch or at least 5.0 / inch after 180 days.

[0010] In yet another embodiment, the foamable polymer composition comprises: a) 85% to 95% by weight of a thermoplastic matrix polymer composition; b) 5.0% to 10% by weight of a blowing agent composition; and c) at least one polymer selected from polyvinylidene dichloride (PVDC), polyvinyl alcohol, polyvinylidene fluoride (PVDF), polyvinyl chloride (PVC), ethylene vinyl alcohol, polyurethane, styrene butadiene (SBR), and combinations or copolymers thereof.

[0011] 1. A method of making a polymer foam, the method comprising: a) providing a matrix polymer melt to an extruder; b) injecting a blowing agent composition into the matrix polymer melt in the extruder to form a foamable polymer composition; d) extruding the foamable polymer composition to form a polymer foam having a first major surface and a second major surface; and e) applying to at least one of the first and second major surfaces of the polymer foam a barrier coating composition comprising a dispersion of at least one polymer selected from the group consisting of polyvinylidene dichloride (PVDC), polyvinyl alcohol, polyvinylidene fluoride (PVDF), polyvinyl chloride (PVC), ethylene vinyl alcohol, polyurethane, styrene butadiene (SBR), and combinations or copolymers thereof, wherein the barrier coating composition forms a barrier coating on at least one of the first and second major surfaces of the polymer foam, thereby forming a coated polymer foam.

[0012] In some embodiments, the barrier coating composition further comprises at least one film-forming additive selected from the group consisting of graphene, nanoclays, inorganic layered particles, and combinations thereof.

[0013] In some embodiments, the blowing agent composition comprises a fluorinated alkene. In some embodiments, the blowing agent comprises 1,1-difluoroethane (HFC-152a), fluoroethane (HFC-161), fluoromethane (HFC-41), HFO-1234ze-E, HFO-1336mzz-Z, HFO-1336mzz-E, HCFO-1233zd-E, HFC-365mfc, methyl formate, methylal, carbon dioxide, one or more hydrocarbons, or a combination thereof.

[0014] According to some embodiments, the matrix polymer of the foamable polymer composition is selected from the group consisting of alkenyl aromatic polymers, styrene polymers, styrene copolymers, styrene block copolymers, polyolefins, vinyl halide polymers, polycarbonates, polyisocyanurates, polyesters, polyacrylates, polyurethanes, phenolic resins, polysulfones, polyphenylene sulfides, acetal resins, polyamides, polyaramids, polyimides, polyetherimides, rubber modified polymers, thermoplastic polymer blends, and combinations thereof.

[0015] In embodiments, the barrier coating is formed on a first major surface and a second major surface of the polymeric foam, hi some embodiments, the barrier coating is formed directly on at least one minor surface of the polymeric foam.

[0016] In embodiments, the method further includes applying the barrier coating composition, where applying the barrier coating composition includes applying the barrier coating using a roller, using a brush, or spraying the barrier coating composition onto at least one of the first major surface and the second major surface.

[0017] In some embodiments, the method includes injecting at least one polymer into a matrix polymer melt in an extruder, the polymer including polyvinylidene dichloride (PVDC), polyvinyl alcohol, polyvinylidene fluoride (PVDF), polyvinyl chloride (PVC), ethylene vinyl alcohol, polyurethane, styrene butadiene (SBR), and combinations or copolymers thereof.

[0018] According to some embodiments, the barrier coating is a first barrier coating on at least one of the first and second major surfaces of the polymer foam, the method further comprising applying a second coating composition to at least one of the first and second major surfaces, the second coating composition forming a second coating on at least one of the first and second major surfaces of the polymer foam. In some embodiments, the second coating composition comprises a dispersion of at least one polymer comprising polyvinylidene dichloride (PVDC), polyvinyl alcohol, polyvinylidene fluoride (PVDF), polyvinyl chloride (PVC), ethylene vinyl alcohol, polyurethane, styrene butadiene (SBR), and combinations or copolymers thereof. In some embodiments, the barrier coating composition and the second coating composition comprise the same polymer. In some embodiments, the barrier coating composition comprises a first polymer and the second coating composition comprises a second polymer different from the first polymer.

[0019] In some embodiments, the method further comprises applying a coating composition comprising a dispersion of polyurethane to at least one of the first major surface and the second major surface of the polymer foam. In embodiments, the dispersion of polyurethane is applied on top of the barrier coating composition. In some embodiments, the barrier coating composition comprises a dispersion of polyvinyl alcohol or ethylene vinyl alcohol.

[0020] The foregoing and other objects, features, and advantages of the general inventive concept will become more readily apparent from a consideration of the following detailed description. [Brief description of the drawings]

[0021] Exemplary embodiments will become apparent from the more particular description of certain exemplary embodiments provided below and illustrated in the accompanying drawings. [Figure 1] FIG. 1 is a schematic diagram of an exemplary extrusion apparatus useful for carrying out the methods according to one or more embodiments shown and described herein. [Diagram 2] 1 is a graph showing k factor (y-axis) as a function of time (x-axis) for various barrier coating configurations according to Example 1. [Diagram 3] 1 is a graph showing k-factor (y-axis) as a function of time (x-axis) for various concentrations of barrier coating composition injected into an extrusion apparatus according to Example 2. [Figure 4] 1 is a graph showing k factor (y-axis) as a function of time (x-axis) for various barrier coating configurations with Coating A according to Example 3. [Diagram 5] 1 is a graph showing k factor (y-axis) as a function of time (x-axis) for various barrier coating configurations with Coating B according to Example 3. [Figure 6] 1 is a graph showing k factor (y-axis) as a function of time (x-axis) for various barrier coating configurations according to Example 4. [Figure 7] 1 is a graph showing k factor (y-axis) as a function of time (x-axis) for various barrier coating configurations according to Example 4. [Figure 8] 1 is a graph showing k factor (y-axis) as a function of time (x-axis) for various barrier coating configurations according to Example 5. [Figure 9] 1 is a graph showing k factor (y-axis) as a function of time (x-axis) for various PVDC coat weight configurations according to Example 6. [Figure 10]1 is a graph showing k factor (y-axis) as a function of time (x-axis) for various samples according to Example 7. [Figure 11] 1 is a graph showing k-factor (y-axis) as a function of time (x-axis) for various samples containing 0.50 wt % isobutane and various barrier coating configurations according to Example 7. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the embodiments belong. Although any methods and materials similar or equivalent to those described herein may be used in the practice or testing of various embodiments, preferred methods and materials are described herein. All references cited herein, including published or corresponding U.S. or foreign patent applications, issued U.S. or foreign patents, or any other references, are each incorporated by reference in their entirety, including all data, tables, figures, and text presented in the cited references. In the drawings, the thickness of lines, layers, and regions may be exaggerated for clarity. It should be noted that like numbers appearing throughout the drawings indicate like elements. The terms "composition" and "composition of the present invention" may be used interchangeably herein.

[0023] As used in this specification and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly dictates otherwise.

[0024] Unless otherwise indicated, all numbers expressing quantities of ingredients, chemical and molecular properties, reaction conditions, and the like used in the specification and claims are to be understood as being modified in all instances by the term "about." Accordingly, unless otherwise indicated, the numerical parameters set forth in the specification and appended claims are approximations that may vary depending upon the desired properties sought to be obtained by the exemplary embodiments of this invention. At the very least, each numerical parameter should be construed in light of the number of significant digits and ordinary rounding approaches.

[0025] Unless otherwise indicated, any element, property, feature, or combination of elements, properties, and features may be used in any embodiment disclosed herein, regardless of whether the element, property, feature, or combination of elements, properties, and features is explicitly disclosed in the embodiment. It will be readily understood that a feature described in relation to any particular aspect described herein may be applicable to other aspects described herein, provided that the feature is compatible with that aspect. In particular, a feature described herein in relation to a method may be applicable to an insulation product, and vice versa. A feature described herein in relation to a method may be applicable to a foamable polymer composition, and vice versa. A feature described herein in relation to an insulation product may be applicable to a foamable polymer composition, and vice versa.

[0026] Every numerical range given throughout this specification and the claims will include every narrower numerical range that falls within such broader numerical range, as if such narrower numerical ranges were all expressly written herein.

[0027] As used herein, the term "blowing agent" is understood to include physical blowing agents (e.g., dissolved gaseous agents) or chemical blowing agents (e.g., gas evolved by decomposition). Blowing agents are generally added to molten polymers under appropriate conditions, for example in an extruder, to initiate foaming and produce a foamed thermoplastic. The blowing agent expands the resin and forms cells (e.g., open or closed pores). As the resin solidifies or hardens, the foam is produced by either the blowing agent trapped in the cells or the ambient air replacing the blowing agent in the cells. The blowing agents discussed herein are preferably environmentally acceptable blowing agents (e.g., they are generally safe for the environment), as recognized by those skilled in the art.

[0028] As used herein, unless otherwise specified, values ​​for blowing agents or other composition components or ingredients are expressed as weight percent or weight % of each component in the composition.

[0029] In the context of this disclosure, "closed cell" refers to a polymer foam having multiple cells, at least 95% of which are closed. However, in this application, the cells may be "open cell" or closed cell (i.e., certain embodiments disclosed herein may exhibit an "open cell" polymer foam structure).

[0030] The present disclosure relates to polymeric foams and polymeric foam products, such as extruded or expanded polystyrene foams, formed from a foamable polymeric material, a blowing agent composition, and a composition containing a barrier coating or barrier additive that stops or slows the rate of diffusion of the blowing agent composition, thereby allowing a lesser amount of the blowing agent composition to be added to achieve comparable physical properties of the resulting foam, or a maintained amount of the blowing agent composition to achieve improved insulating properties of the resulting foam. As described in more detail herein, a barrier coating can be provided on at least one major surface of the resulting foam product and / or can be incorporated into the foamable composition, depending on the particular embodiment.

[0031] Figure 1 illustrates a conventional extrusion apparatus 100 useful for carrying out methods according to various embodiments. The extrusion apparatus 100 may comprise a single or double (not shown) screw extruder comprising a barrel 102 around a screw 104 with a spiral flight 106 disposed thereon and configured to compress and thereby heat material introduced into the screw extruder. As illustrated in Figure 1, the polymer composition may be conveyed to the screw extruder from one or more (not shown) feed hoppers 108 as a flowable solid, such as beads, granules or pellets, or as a liquid or semi-liquid melt.

[0032] As the basic polymer composition progresses through the screw extruder, the spacing of the flights 106 decreases, defining successively smaller spaces through which the polymer composition is forced to flow by the rotation of the screw. This decreasing volume acts to increase the temperature of the polymer composition to obtain a polymer melt (if solid starting materials are used) and / or to increase the temperature of the polymer melt.

[0033] As the polymeric composition progresses through the screw extruder 100, one or more ports may be provided through the barrel 102 with associated apparatus 110, 112 for injecting one or more blowing agents and optional additives into the polymeric composition. In some embodiments, the barrier coating composition may be added through one or more of the ports, as described in more detail below. Once the blowing agent is introduced into the polymeric composition, the resulting mixture is subjected to a degree of blending sufficient to distribute each component approximately uniformly throughout the polymeric composition to obtain a polymeric foamable composition.

[0034] The polymeric foamable composition is then forced to flow through the extrusion die 114 and exits the die into a region of low pressure (which may be below atmospheric pressure) thereby allowing the blowing agent to expand and produce the polymeric foam material. This pressure reduction may be achieved gradually as the extruded polymeric foamable composition travels through successively larger openings in the die, or through some suitable device (not shown) downstream of the extrusion die to control, to some extent, the manner in which the pressure applied to the polymeric foamable composition is reduced. The polymeric foam material may also be subjected to additional processing such as coating, calendaring, water dipping, cooling sprays, or other operations to control the thickness and other properties of the resulting polymeric foam product.

[0035] In any of the exemplary embodiments, a barrier coating composition may be applied to the polymeric foam product. The barrier coating composition may be applied to one or more major surfaces of the polymeric foam product, for example, using any one of a variety of coating methods. For example, the barrier coating composition may be applied by roller, brush, spray coating method, dip coating, spin coating, flow coating, curtain coating, and the like. Other coating methods known and used in the art may be used depending on the particular embodiment. The barrier coating composition is then dried to form a barrier coating on the surface of the polymeric foam product. Although described as being applied to one or more major surfaces of the polymeric foam product, it should be understood that the barrier coating composition may additionally or alternatively be applied to one or more smaller surfaces of the polymeric foam product. For example, the barrier coating composition may be applied to one or more edges of the resulting polymeric foam product in addition to or alternatively to the top and / or bottom surfaces of the resulting polymeric foam product. The barrier coating may be applied to form a continuous coating on one or more surfaces of the polymeric foam product, or the barrier coating may form only a partial discontinuous coating on one or more surfaces.

[0036] The barrier coating composition may be applied directly to the surface of the polymeric foam product without an intervening layer. Additional coating layers, including additional coating layers of the barrier coating composition, can be applied over the first barrier coating composition layer. However, in some embodiments, it is contemplated that one or more layers can be applied between the barrier coating composition and the surface of the polymeric foam product such that the barrier coating composition is applied indirectly to the surface of the polymeric foam product (e.g., the barrier coating composition is applied in a layer over the surface of the polymeric foam product).

[0037] In any of the exemplary embodiments, the barrier coating composition may comprise a dispersion, solution, or emulsion that includes one or more polymers. Polymers include poly(vinylidene chloride) (PVdC), polyvinyl alcohol (PVOH), poly(ethylene-co-vinyl alcohol) (EVOH), poly(vinylidene fluoride) (PVdF), polyurethanes, styrene butadiene (SBR), polyvinylidene fluoride (PVDF), polyvinyl chloride (PVC), poly(acrylates) and copolymers, polyamides (e.g., nylon-6), polyesters (e.g., PET), polystyrene (PS), polyglycolic acid (PGA), poly(ethylene 2,5-furandicarboxylate) (PEF), poly(butylene succinate) (PBS), bio-based ethylene glycol (BGE), and ethylene glycol esters (EGFR). Other polymers may be incorporated that can impart gas barrier properties to the coating. In some embodiments, the polymer can be added in solid (e.g., resin) or molten (e.g., liquid) form instead of a dispersion, solution, or emulsion, such as when the barrier coating composition is added as part of a polymeric foamable composition. When the polymer is added in the form of a dispersion, the dispersion can be an aqueous dispersion (e.g., the polymer is dispersed in water) or a solvent-based dispersion.

[0038] The polymer may be included in the barrier coating composition as a dispersion or emulsion having a solids content of from about 20% to about 65% by weight, based on the total weight of the composition, including a solids content of from about 25% to about 62% by weight, from about 35% to about 60% by weight, from about 40% to about 58% by weight, from about 45% to about 56% by weight, or any other range or subrange contained therein.

[0039] In some embodiments, the polymer may also be characterized by the amount of polymer present in the barrier coating composition based on the total amount of solids present in the barrier coating composition. For example, the polymer may be present in an amount of about 40% to about 100% by weight, including, for example, about 50% to about 98% by weight, about 60% to about 96% by weight, about 70% to about 93% by weight, and about 75% to about 90% by weight (including any other endpoints or subranges contained therein), based on the total amount of solids present in the barrier coating composition.

[0040] Optionally, the barrier coating composition further comprises one or more film-forming additives. The film-forming additives can include, by way of example and without limitation, graphene, nanoclay, or inorganic layered particles. Suitable film-forming additives include, by way of example and without limitation, cellulose nanocrystals (CNC), organosilanes, perfluoroalkyl ethyl methacrylate (PPFEMA), ormocer, biowax / wax, nanoclay / clay, silicon oxide (SiO x), aluminum oxide film (Al2O3), graphene / graphene oxide, molybdenum disulfide (MoS2), tungsten disulfide (WS2), niobium selenide (NbSe2), hexagonal boron nitride (hBN), and combinations thereof. The film-forming additive may aid the barrier coating composition in forming a continuous film on the surface of the polymer foam product and contribute to the barrier properties of the barrier coating. When included, the film-forming additive may be included in the barrier coating composition in an amount of 0.1 wt.% to 50 wt.%, including 0.5 wt.% to 25 wt.%, 1 wt.% to 20 wt.%, or 5 wt.% to 15 wt.%, of the barrier coating composition, based on the total amount of solids present in the composition.

[0041] Optionally, the barrier coating composition may include one or more fillers, such as platelet-type additives, such as inorganic layered particles, including graphene, nanoclay, mica, talc, and aluminum flakes, or combinations thereof. In some exemplary embodiments, the one or more fillers may be included at at least 0.25 wt.% of the barrier coating composition, based on the total amount of solids present in the composition. The one or more fillers may be included at about 0.5 wt.% to about 50 wt.%, including about 1 wt.% to about 35 wt.%, about 5 wt.% to about 30 wt.%, and about 10 wt.% to about 25 wt.%, including any endpoints and subranges therebetween, of the barrier coating composition, based on the total amount of solids present in the composition.

[0042] In some exemplary embodiments, the asphalt composition further comprises various oils, fire retardant materials, and other compounds that are traditionally added to asphalt compositions for roofing applications. The barrier coating composition may optionally further comprise one or more other additives, such as rheology modifiers, UV absorbers / stabilizers, fire retardants, pigments, or additives to provide wettability. Other additives are also contemplated and possible. The amount of any such additives may vary depending on the particular embodiment, and generally may be from 0.1% to 30% by weight, including from 0.2% to 25%, from 0.5% to 20%, from 0.7% to 18%, from 1% to 15%, from 2% to 12%, from 2.5% to 10%, or from 5% to 8% by weight (including any endpoints and subranges therebetween) of the barrier coating composition, based on the total solids present in the composition.

[0043] The polymer, optional film-forming additive, and optional other additives can be dispersed in water and / or a solvent and blended to form a barrier coating composition. As described above, the barrier coating composition is applied to at least one major surface of the polymeric foam product and dried to form a barrier coating on the surface. In some exemplary embodiments, the barrier coating is formed directly on the surface of the polymeric foam product without the use of an adhesive, primer, or other layer between the barrier coating and the surface of the polymeric foam product. Thus, in any of the embodiments disclosed herein, the polymeric foam product does not include any polyamide primer coating applied to the foam product prior to the barrier coating composition.

[0044] Instead of, or in addition to, the coating layers described above, the barrier coating composition may be injected into the extruder, such as through a port, and incorporated directly into the foamable composition.

[0045] The foamable polymer composition provides strength, flexibility, toughness, and durability to the final product. The foamable polymer composition is not particularly limited, and generally any polymer that can be foamed can be used as the foamable polymer (referred to herein as the "matrix polymer") in the resin mixture. The matrix polymer may be thermoplastic or thermosetting. The particular polymer composition may be selected to provide sufficient mechanical strength and / or process utilized to form the final foamed polymer product. In addition, the matrix polymer is preferably chemically stable, i.e., generally non-reactive within the temperature range expected during the formation and subsequent use of the polymer foam.

[0046] As used herein, the term "polymer" is generic to the terms "homopolymer," "copolymer," "terpolymer," and combinations of homopolymers, copolymers, and / or terpolymers. Non-limiting examples of foamable polymers suitable for use as the matrix polymer herein include alkenyl aromatic polymers, polyvinyl chloride ("PVC"), chlorinated polyvinyl chloride ("CPVC"), polyethylene, polypropylene, polycarbonate, polyisocyanurate, polyetherimide, polyamide, polyester, polycarbonate, polymethylmethacrylate, polyacrylate, polyphenylene oxide, polyurethane, phenolic resins, polyolefins, styrene acrylonitrile ("SAN"), acrylonitrile butadiene styrene, acrylic / styrene / acrylonitrile block terpolymer ("ASA"), polysulfone, polyurethane, polyphenylene sulfide, acetal resins, polyamides, polyaramids, polyimides, polyacrylic esters, copolymers of ethylene and propylene, copolymers of styrene and butadiene, copolymers of vinyl acetate and ethylene, rubber modified polymers, thermoplastic polymer blends, and combinations thereof.

[0047] In some exemplary embodiments, the foamable matrix polymer is an alkenyl aromatic polymer material.Suitable alkenyl aromatic polymer materials include alkenyl aromatic homopolymers and copolymers of alkenyl aromatic compounds and copolymerizable ethylenically unsaturated comonomers.In addition, the alkenyl aromatic polymer material may contain a small amount 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 each of alkenyl aromatic homopolymers and copolymers, or blends thereof with non-alkenyl aromatic polymers.

[0048] Examples of alkenyl aromatic polymers include, but are not limited to, alkenyl aromatic polymers derived from alkenyl aromatic compounds such as styrene, alpha-methylstyrene, ethylstyrene, vinylbenzene, vinyltoluene, chlorostyrene, and bromostyrene. In at least one embodiment, the alkenyl aromatic polymer is polystyrene.

[0049] In some embodiments, small amounts of monoethylenically unsaturated monomers, such as C2-C6 alkyl acids and esters, ionomeric derivatives, and C2-C6 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.

[0050] In some embodiments, the matrix polymer may be substantially formed of polystyrene (e.g., greater than 95%), and in certain exemplary embodiments, may be completely formed of polystyrene. The matrix polymer may be present in the foamable polymer composition in an amount of about 60% to about 99% by weight, about 60% to about 96% by weight, about 70% to about 95% by weight, or about 85% to about 94% by weight. In some embodiments, the matrix polymer may be present in an amount of about 90% to about 99% by weight. As used herein, the terms "% by weight" and "wt. %" are used interchangeably and are meant to indicate a percentage based on 100% of the total weight of the dry ingredients.

[0051] As described herein, in any of the exemplary embodiments, the barrier coating composition described herein may be incorporated into a foamable polymer composition. For example, instead of applying the barrier coating composition as a coating onto at least one surface of a polymeric foam product, the barrier coating composition may be injected into the screw extruder 100. In embodiments where the polymer of the barrier coating composition is a resin, the polymer may be introduced into the feed hopper 108 in pellet form. It should be understood that the specific properties of the barrier coating composition when injected into the extruder may be different from the properties of the barrier coating composition intended to be coated onto the surface of the polymeric foam product, including, but not limited to, the viscosity of the coating composition and the solids loading of the barrier coating composition.

[0052] As shown above, the polymer foam is formed from a composition containing a blowing agent composition. According to one aspect of the present invention, the blowing agent composition includes one or more of CO2, fluorinated blowing agents such as hydrofluorocarbons (HFCs), hydrochlorofluorocarbons, hydrofluoroethers, hydrofluoroolefins (HFOs), hydrochlorofluoroolefins (HCFOs), hydrobromofluoroolefins, hydrofluoroketones, hydrochloroolefins, and fluoroiodocarbons, alkyl esters such as methyl formate, ethanol, water, hydrocarbons, or mixtures thereof. In other exemplary embodiments, the blowing agent includes one or more of CO2, ethanol, HFOs, HCFOs, HFCs, and mixtures thereof.

[0053] In any of the exemplary embodiments, the blowing agent composition may include materials having low global warming potential ("GWP"), such as fluorinated alkenes, including, for example, hydrofluoroolefins (HFOs) and hydrochlorofluoroolefins (HCFOs). Hydrofluoroolefin blowing agents in the blowing agent composition of the present invention include, for example, 3,3,3-trifluoropropene (HFO-1243zf); 2,3,3-trifluoropropene; (cis and / or trans)-1,3,3,3-tetrafluoropropene (HFO-1234ze), especially 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-1234yf); 1,1,3,3,3-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;Octane Fluoro-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-1336mzz);1,2-Difluoroethene (HFO-1132);1,1,1,2,4,4,4-Heptafluoro-2-butene;3-Fluoropropene, 2,3-Difluoropropene;1,1,3-Trifluoropropene Pen;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;Included may be 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; 1,1,2,3,4,4,4-heptafluoro-1-butene; and 1,3,3,3-tetrafluoro-2-(trifluoromethyl)-propene. In some exemplary embodiments, the blowing agent or co-blowing agent comprises HFO-1234ze and / or HFO-1336mzz.;

[0054] In some exemplary embodiments, fluorinated alkene blowing agents include, for example, 1,1,1,4,4,4-hexafluoro-2-butene (HFO-1336mzz), including its cis (HFO-1336mzz-Z) and / or trans (HFO-1336mzz-E) isomers; and (cis and / or trans)-1,3,3,3-tetrafluoropropene (HFO-1234ze), particularly the trans isomer. HFO-1336mzz-Z has a GWP of 2 and an ozone depletion potential (ODP) of 0. HFO-1336mzz-Z is commercially available under the trade name Opteon™ 1100. Similarly, HFO-1234ze has a GWP of less than 1 and an ODP of 0. In some exemplary embodiments, the low GWP fluorinated alkene has a GWP of less than 50, e.g., less than 30, less than 25, less than 15, less than 10, less than 5, less than 2.5, or less than 1. In any of the exemplary embodiments, the blowing agent may comprise HFO-1336mzz-Z and is substantially free of additional fluorinated alkenes.

[0055] When included, the fluorinated alkene is present in the blowing agent composition at at least 5% by weight, including at least 7% by weight, at least 10% by weight, at least 12% by weight, at least 15% by weight, at least 18% by weight, at least 20% by weight, at least 23% by weight, at least 25% by weight, at least 27% by weight, and at least 30% by weight. In any of the exemplary embodiments, the fluorinated alkene is present in the blowing agent composition in an amount of 98% by weight or less, including an amount of 95% by weight or less, 90% by weight or less, 85% by weight or less, 80% by weight or less, 75% by weight or less, 70% by weight or less, 65% by weight or less, 60% by weight or less, 55% by weight or less, 52% by weight or less, 50% by weight or less, 47% by weight or less, 45% by weight or less, 42% by weight or less, 40% by weight or less, 37% by weight or less, 35% by weight or less, 32% by weight or less, 30% by weight or less, and 25% by weight or less. In any of the exemplary embodiments, the fluorinated alkene may be present in the blowing agent composition in an amount from 5% to 98% by weight, including, for example, from 5% to 85% by weight, from 5% to 75% by weight, from 5% to 55% by weight, from 10% to 50% by weight, from 12% to 45% by weight, and from 15% to 40% by weight (including all endpoints and subranges therebetween).

[0056] Alternatively, the amount of fluorinated alkene may be characterized by the amount present in the foamable polymer composition. Thus, when so characterized, the fluorinated alkene may be present in the foamable polymer composition at at least 0.3 wt%, including at least 0.5 wt%, at least 0.7 wt%, at least 1.0 wt%, at least 1.2 wt%, at least 1.5 wt%, at least 2.0 wt%, at least 2.3 wt%, at least 2.5 wt%, at least 2.7 wt%, at least 3.0 wt%, at least 3.5 wt%, at least 3.7 wt%, at least 3.9 wt%, and at least 4.0 wt%. In any of the exemplary embodiments, the fluorinated alkene may be present in the foamable polymer composition in an amount of 10.0 wt% or less, including amounts of 8.0 wt% or less, 6.0 wt% or less, 4.5 wt% or less, 4.0 wt% or less, 3.8 wt% or less, 3.5 wt% or less, 3.2 wt% or less, 3.0 wt% or less, 2.8 wt% or less, 2.5 wt% or less, 2.3 wt% or less, and 2.0 wt% or less.

[0057] Alternatively, the amount of fluorinated alkene may be characterized by the molar amount per 100 grams of matrix polymer. Thus, when characterized in this manner, the fluorinated alkene may be present in the foamable polymer composition in an amount less than 0.1 moles (including 0.05 moles or less, 0.03 moles or less, 0.02 moles or less, 0.018 moles or less, and 0.01 moles or less) per 100 grams of matrix polymer. In any of the exemplary embodiments, the fluorinated alkene may be present in the foamable polymer composition in an amount from 0.0005 moles to less than 0.1 moles per 100 grams of matrix polymer, including 0.001 moles to 0.025 moles, 0.005 moles to 0.02 moles, and 0.01 moles to 0.015 moles (including all endpoints and subranges therebetween).

[0058] In various embodiments, the blowing agent composition may optionally include one or more blowing agents or co-blowing agents selected from the group consisting of hydrocarbons, hydrofluorocarbons ("HFCs"), hydrochlorofluorocarbons ("HCFOs"), carbon dioxide, methyl formate, methylal, and water.

[0059] In some exemplary embodiments, the blowing agent may include one or more hydrocarbons. Suitable hydrocarbons include, but are not limited to, C1-C6 aliphatic hydrocarbons, such as methane, ethane, propane, n-butane, isobuatane, and neopentane, and C1-C3 aliphatic alcohols, such as methanol, ethanol, n-propanol, and isopropyl alcohol.

[0060] In some exemplary embodiments, the blowing agent may include one or more hydrofluorocarbons. The specific 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 (HF0-1234ze), pentafluoro-ethane (HFC-125), fluoroethane (HFC-161), 1,1,2,2,3,3-hexafluoropropane (HFC-236ca), 1,1,1,2,3,3-hexafluoroethane ... Examples of suitable blowing agents include 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. In some exemplary embodiments, the blowing agent comprises HFC-152a. Exemplary HFC blowing agents or blends thereof are commercially available under the trade name FORMACEL™ and include, but are not limited to, FORMACEL™ B and FORMACEL™ Z6.

[0061] Exemplary blowing agent compositions include 15 wt% to 60 wt% of a fluorinated alkene selected from HFO-1336mzz and HFO-1234ze or mixtures thereof, 40 wt% to 85 wt% of HFC-152a, and optionally carbon dioxide, based on the total weight of the blowing agent composition, including all endpoints and subranges therebetween. Stated differently, exemplary blowing agent compositions may include 2.0 wt% to 4.5 wt% of HFO-1336mzz, 3.5 wt% to 5.0 wt% of HFC-152a, and optionally carbon dioxide, based on the total weight of the foamable polymer composition, including compositions including 2.5 wt% to 4.0 wt% of HFO-1336mzz, 4.2 wt% to 4.9 wt% of HFC-152a, and optionally carbon dioxide, based on the total weight of the foamable polymer composition. Further exemplary blowing agent compositions may include 3.0 wt.% to 5.0 wt.% HFO-1234ze, 2.5 wt.% to 4.5 wt.% HFC-152a, and optionally carbon dioxide, based on the total weight of the foamable polymer composition, including compositions including 3.5 wt.% to 4.5 wt.% HFO-1234ze, 3.0 wt.% to 3.9 wt.% HFC-152a, and optionally carbon dioxide, based on the total weight of the foamable polymer composition.

[0062] The blowing agent may also include one or more hydrochlorofluoroolefins (HCFOs), such as 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-pentafluorobutane (HFC-365mfc); 1,1,1,2,3,3,3-heptafluoropropane (HFC-227ea); tnchlorofluoromethane (CFC-11); dichlorodifluoromethane (CFC-12); and dichlorofluoromethane (HCFC-22).

[0063] 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 generically to refer to 1,1,1-trifluoro-3-chloro-propene, regardless of whether it is the cis or trans form. The terms "cisHCFO-1233zd" and "transHCFO-1233zd" are used herein to describe the cis and trans forms or trans isomers of 1,1,1-trifluoro,3-chloropropene, respectively.

[0064] In some exemplary embodiments, the blowing agent composition includes two or more blowing agents, such as a hydrocarbon and carbon dioxide. In other exemplary embodiments, the blowing agent formulation may be free of carbon dioxide and / or water. In various exemplary embodiments, the blowing agent composition is free of hydrofluorocarbons.

[0065] In some embodiments, the blowing agent comprises CO2, optionally one or more co-blowing agents (e.g., hydrocarbons, HFOs, and / or HFCs), and optionally one or more solubilizing agents (e.g., methyl formate, ethanol, isobutane, propylene carbonate, etc.). In some such embodiments, CO2 may be present in an amount of 25% or more, 50% or more, 60% or more, 70% or more, 80% or more, 90% or more, 95% or more, or even 98% or more by weight based on the total weight of the blowing agent composition. Exemplary blowing agent compositions include 50% to 99% by weight CO2 and 1% to 20% by weight of one or more hydrocarbons, such as isobutane, 65% to 98% by weight CO2 and 2.0% to 15% by weight of one or more hydrocarbons, and 80% to 96% by weight CO2 and 3% to 12% by weight of one or more hydrocarbons.

[0066] In some exemplary embodiments, the blowing agent is present in the blowing agent composition at at least 0.1 wt%, including at least 1 wt%, at least 5 wt%, at least 10 wt%, at least 15 wt%, at least 17 wt%, at least 20 wt%, at least 25 wt%, at least 28 wt%, at least 30 wt%, at least 33 wt%, at least 35 wt%, at least 40 wt%, at least 43 wt%, at least 45 wt%, at least 47 wt%, and at least 50 wt%. The amount of blowing agent present in the blowing agent composition can vary depending on the particular embodiment. For example, blowing agents such as carbon dioxide or water may be included in small amounts due to their low solubility in polystyrene, while blowing agents with improved solubility in polystyrene may be included in larger amounts (e.g., at least 15 wt%). However, in some embodiments, the blowing agent such as carbon dioxide may be provided with a solubilizing agent to increase the solubility of the blowing agent in polystyrene. In any of the exemplary embodiments, the blowing agent is present in the blowing agent composition in an amount of 75% by weight or less, including an amount of 70% by weight or less, 67% by weight or less, 65% by weight or less, and 62% by weight or less. In any of the exemplary embodiments, the blowing agent may be present in the blowing agent composition in an amount of 0.1% by weight to 75% by weight, including, for example, 1% by weight to 75% by weight, 5% by weight to 75% by weight, 10% by weight to 75% by weight, 25% by weight to 75% by weight, 30% by weight to 70% by weight, 32% by weight to 67% by weight, and 36% by weight to 63% by weight.

[0067] When characterizing the blowing agent by its weight percent present in the foamable polymer composition, the blowing agent is present at at least 3.0 weight percent, including at least 3.2 weight percent, at least 3.5 weight percent, at least 3.7 weight percent, and at least 3.9 weight percent. In any of the exemplary embodiments, the blowing agent may be present in the foamable polymer composition in an amount of 10.0 weight percent or less, including amounts of 9.0 weight percent or less, 8.5 weight percent or less, 8.0 weight percent or less, 7.8 weight percent or less, 7.5 weight percent or less, 7.2 weight percent or less, 7.0 weight percent or less, 6.8 weight percent or less, 6.5 weight percent or less, 6.3 weight percent or less, 6.0 weight percent or less, 5.5 weight percent or less, 5.0 weight percent or less, 4.8 weight percent or less, 4.5 weight percent or less, 4.2 weight percent or less, 4.0 weight percent or less, and 3.9 weight percent or less.

[0068] Alternatively, the amount of blowing agent may be characterized by the amount in moles per 100 grams of matrix polymer. Thus, when so characterized, the first blowing agent may be present in the foamable polymer composition in an amount from 0.001 moles to less than 0.1 moles per 100 grams of matrix polymer, including from 0.01 moles to 0.09 moles, from 0.03 moles to 0.08 moles, and from 0.04 moles to 0.075 moles per 100 grams of matrix polymer.

[0069] In embodiments where the barrier coating composition is injected into a screw feeder or otherwise incorporated into a foamable polymer mixture, it should be understood that the water included in the barrier coating composition adds to the amount of blowing agent and therefore the foaming power of the blowing agent.

[0070] Surprisingly, it has been discovered that the use of the barrier coating compositions described herein can reduce the amount of blowing agent used incorporated into the foamable polymer mixture and result in a foam product having improved thermal insulation values ​​compared to an otherwise identical foam product without the barrier coating. For example, the blowing agent composition (i.e., the total amount of all blowing agents) is typically present in the foamable mixture in an amount of about 6.0% to 12.0% by weight, more specifically, in an amount of 7.8% to 8.0% by weight, based on the total weight of the foamable polymer mixture. However, in some exemplary embodiments, the total blowing agent composition present in the foamable polymer mixture can be reduced to an amount of less than 7.6% by weight, such as from about 1% to about 6.8% by weight, and in some embodiments, from about 2% to about 6.65% by weight, or from about 2.5% to about 6.4% 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 2.6 to about 4.5 wt.%, including from about 2.8 to about 4.2 wt.%, based on the total weight of the foamable composition excluding the blowing agent composition.

[0071] Optional additives such as infrared attenuators, processing aids, nucleating agents, plasticizers, pigments, elastomers, extrusion aids, antioxidants, fillers, antistatic agents, biocides, termiticides, surfactants, colorants, oils, waxes, flame retardant synergists, and / or UV absorbers / stabilizers can be incorporated into the foamable composition. These optional additives may be included in amounts necessary to obtain the desired characteristics of the foamable gel or the resulting extruded foam product. The additives may be added to the foamable composition or may be incorporated into the foamable composition before, during, or after the polymerization process used to make the polymer.

[0072] As mentioned above, the foamable composition may further contain at least one infrared attenuating agent (IAA) to increase the R-value of the resulting foam product. Non-limiting examples of infrared attenuating agents suitable for use in the present compositions include graphite, including nanographite, carbon black, powdered amorphous carbon, asphalt, granular asphalt, ground glass, talc, glass fiber strands, mica, black iron oxide, metal flakes (e.g., aluminum flakes), carbon nanotubes, platelet nanographene, carbon nanofibers, activated carbon, titanium dioxide, and combinations thereof. In some exemplary embodiments, the infrared attenuating agent is present in the foamable composition in an amount of 0-5.0% by weight of the total composition. In other embodiments, the infrared attenuating agent may be present in an amount of 0.05-3.0% by weight, 0.08-2.0% by weight, or 0.1-1.0% by weight. In some exemplary embodiments, the infrared attenuating agent is present in the composition in an amount of 0.5% by weight or less.

[0073] In at least one exemplary embodiment, the infrared attenuating agent is nanographite. The nanographite can be multi-layered by furnace high temperature expansion from acid-treated natural graphite or microwave heating expansion from moisture-saturated natural graphite. Additionally, the nanographite can be multi-layered nanographite with at least one dimension having a thickness of less than 100 nm. In some exemplary embodiments, the graphite can be mechanically processed, such as by air jet milling to break down the nanographite particles. The grinding of the particles ensures that the nanographite flakes and other dimensions of the particles are less than 150 microns.

[0074] The nanographite may or may not be chemically or surface modified and may be incorporated into polyethylene methyl acrylate copolymer (EMA) which is used as both a medium and a carrier for the nanographite. Other possible carriers for the nanographite include, but are not limited to, polymeric carriers such as polymethyl methacrylate (PMMA), polystyrene, polyvinyl alcohol (PVOH), and polyvinyl acetate (PVA). In an exemplary embodiment, the nanographite is substantially uniformly distributed throughout the foam. As used herein, the phrase "substantially uniformly distributed" is meant to indicate that a substance (e.g., nanographite) is uniformly or nearly uniformly distributed within the foam.

[0075] Although infrared attenuating agents increase the R-value of foams containing HFO and / or HFC blowing agents, the addition of infrared attenuating agents also tends to reduce the cell size of the cells in the foam, resulting in an undesirable final foamed product. In particular, small cell size tends to increase board bulk density, increase product cost, and reduce process window during extrusion process. However, it has surprisingly been discovered that the amount of infrared attenuating agents included in the foamable composition can be reduced or eliminated when the barrier coating composition is applied to or within the polymer foam. Thus, in any of the exemplary embodiments, the foamable polymer composition and the resulting foam product include less than 0.25 wt. % of an infrared attenuating agent such as graphite, including less than 0.2 wt. %, less than 0.15 wt. %, less than 0.10 wt. %, and less than 0.05 wt. %. In any of the exemplary embodiments, the foamable polymer composition and the resulting polymer foam do not include an infrared attenuating agent such as graphite. It should be appreciated that such embodiments may include a nucleating agent (e.g., inorganic materials such as talc, clay, and / or calcium carbonate) in the foamable polymer composition to control the foam cell size.

[0076] The foamable composition may further contain a flame retardant in an amount of up to 5.0 wt% or more. For example, flame retardant chemicals can be added during the extrusion foam manufacturing process to impart flame retardant characteristics to the extruded foam product. Non-limiting examples of flame retardant chemicals suitable for use in the compositions of the present invention include brominated aliphatic compounds such as hexabromocyclododecane (HBCD) and pentabromocyclohexane, brominated phenyl ethers, esters of tetrabromophthalic acid, halogenated polymeric flame retardants such as brominated polymeric flame retardants, phosphate compounds, and combinations thereof.

[0077] Once the blowing agent composition, barrier coating composition, and optional additional additives have been introduced into the foamable polymer composition, the resulting mixture is subjected to some additional blending sufficient to generally uniformly distribute each of the additives throughout the polymer composition to obtain the extruded or foamable composition.

[0078] The foamable polymer compositions disclosed herein can be used to produce rigid foamed polymer insulation products through an extrusion process. The extruded foam has a cellular structure with cells defined by cellular membranes and struts. The struts form at the intersections of the cellular membranes, and the cellular membranes cover the interconnecting cellular windows between the struts.

[0079] In some exemplary embodiments, the polymeric insulation product has an average density of less than 10 pcf (pounds per cubic foot), including less than 5 pcf, less than 3 pcf, and less than 2.5 pcf, when produced at atmospheric conditions. However, if the polymeric insulation product is produced under high vacuum, the density may be lower. In any of the exemplary embodiments, the polymeric insulation product has a density of 2.40 pcf or less, or 2.25 pcf or less, or 2.20 pcf or less, or 2.00 pcf or less, or 1.60 pcf or less. In any of the exemplary embodiments, the polymeric insulation product has an average density of 1.40 pcf to 2.40 pcf, including 1.40 pcf to 2.25 pcf, 1.40 pcf to 2.00 pcf, 1.40 pcf to 1.60 pcf, 1.45 pcf to 1.55 pcf, 2.10 pcf to 2.30 pcf, and 2.20 pcf to 2.28 pcf.

[0080] It should be understood that the phrase "substantially closed cell" is meant to indicate that all or nearly all of the cells in the cellular structure of the polymeric insulation product are closed. For example, "substantially closed cell" may be meant to indicate that 30.0% or less of the cells are open cells, and in particular, 10.0% or less, or 5.0% or less are open cells or otherwise "not closed" cells. The closed cell structure helps to increase the R-value of the formed foamed insulation product. However, it should be understood that while it is within the scope of various embodiments to produce an open cell structure, such an open cell structure is not an exemplary embodiment.

[0081] The average cell size of the polymeric insulation product may range from 0.005 mm (5 microns) to 0.6 mm (600 microns), and in some exemplary embodiments, from 0.05 mm (50 microns) to 0.4 mm (400 microns), or from 0.1 mm (100 microns) to 0.2 mm (200 microns).

[0082] Additionally, polymeric insulation products made from the foamable polymer compositions disclosed herein exhibit insulation values ​​(R-values) greater than 4.0 / inch and maintain an R-value of at least 4.0 after 180 days. In any of the exemplary embodiments, the R-value is greater than 5.0 / inch, or greater than 6.0 / inch, or greater than 7.0 / inch. Thus, in some embodiments, the polymeric insulation products may include R-values ​​from 5.0 to greater than 7.0 or 8.0 / inch. The polymeric insulation products may be used to form a variety of products, such as rigid insulation boards, insulating foams, packaging products, building insulation, and underground insulation (e.g., highway, airport runway, railroad, and underground utility insulation).

[0083] The expandable polymer composition can additionally produce extruded foams having high compressive strength, which defines the ability of the foam material to withstand axial pushing forces. In some exemplary embodiments, the expandable polymer composition has a compressive strength within the desired range for extruded foam, which is about 6-120 psi. In some exemplary embodiments, the expandable polymer composition has a compressive strength of 10-110 psi, including 20-100 psi, 30-80 psi, and 35-60 psi. In various exemplary embodiments, the expandable polymer composition has a compressive strength of 40-50 psi.

[0084] Thus, in any of the embodiments described herein, one or more additional coatings may be applied onto the surface of the polymeric foam product. Such additional coatings may be added, for example, to enhance the properties of the barrier coating or to protect the barrier coating. In some embodiments, the one or more additional coatings may impart hydrophobicity or water resistance to the coated polymeric foam product. It is understood that the at least one additional coating may be formed by applying a coating composition to a surface and allowing the coating composition to dry, thereby forming the at least one additional coating. The coating composition may be, for example, a dispersion (e.g., aqueous or solvent-based), a liquid, or the like.

[0085] As mentioned above, the one or more additional coatings may be applied on top of the barrier coating such that the barrier coating is disposed between the one or more additional coatings and the polymeric foam product. In other embodiments, the one or more additional coatings may be applied between the barrier coating and the surface of the polymeric foam product. The one or more additional coatings are not particularly limited and may be the same as or different from the barrier coating. In some embodiments, the barrier coating is a first layer of a coating and the at least one additional coating is a second layer of the same coating. In some embodiments, the barrier coating comprises a first polymer comprising polyvinylidene dichloride (PVDC), polyvinyl alcohol, polyvinylidene fluoride (PVDF), polyvinyl chloride (PVC), ethylene vinyl alcohol, polyurethane, styrene butadiene (SBR), and combinations or copolymers thereof, and the at least one additional coating comprises a different polymer comprising polyvinylidene dichloride (PVDC), polyvinyl alcohol, polyvinylidene fluoride (PVDF), polyvinyl chloride (PVC), ethylene vinyl alcohol, polyurethane, styrene butadiene (SBR), and combinations or copolymers thereof. In embodiments, the at least one additional coating comprises one or more polyurethanes, epoxies, acrylics, or combinations thereof.

[0086] The inventive concept has been described above both generally and with reference to various exemplary embodiments. Although the general inventive concept has been described in what is considered to be exemplary illustrative embodiments, a wide variety of alternative forms known to those skilled in the art can be selected within the general disclosure. In addition, the following examples are intended to better illustrate the present invention, but do not limit the general inventive concept of the present invention in any way.

[0087] Example 1 A barrier coating composition comprising an aqueous dispersion of SBR was brush applied to one or more surfaces of one inch samples of extruded polystyrene foam samples and allowed to dry to form a barrier coating. The application locations of the barrier coating composition are shown in Table 1 below.

[0088] [Table 1]

[0089] As shown in FIG. 2, each of the samples (Samples A-C) that were coated with the barrier coating composition on at least the top and bottom exhibited improved thermal properties (lower k values ​​and increased R values) compared to the control sample (Comparative Sample A) and the sample that was edge-coated only (Sample D).

[0090] Example 2 A co-rotating twin-screw single-screw tandem extrusion foam line was used to prepare the extruded polystyrene foam samples. The polystyrene was melted in the extruder and mixed with the injected blowing agent composition to form a homogenous foamable composition. The foamable composition (excluding the blowing agent) contained 100% by weight polystyrene, a flame retardant masterbatch, and a graphite masterbatch, and is reported as "Solids" in Table 2 below. An aqueous dispersion of SBR (50% by weight solids in water) was injected directly into the extruder at various concentrations. The blowing agent blend was included at a constant amount across all samples. The foamable compositions were then extruded to produce 1 inch XPS foam samples. Each foamable composition is shown in Table 2 below.

[0091] [Table 2]

[0092] Table 3 below lists the properties of the resulting XPS foam samples.

[0093] [Table 3]

[0094] As shown in Table 3 and Figure 3, the XPS foams produced containing SBR dispersions in amounts between 0.05 wt% and 0.25 wt% exhibited improved insulating properties (e.g., lower k values) compared to the control (Comparative Sample B). In addition, the data shown in Table 3 indicates that the barrier coating composition can be infused during the foaming process without adversely affecting the foam properties. For example, the compressive strength and compressive modulus of each example were increased compared to the control (Comparative Sample B).

[0095] Example 3 Varying amounts of one of two types of barrier coatings (either an aqueous dispersion of ethylene vinyl alcohol (EVOH) or an aqueous dispersion of polyvinyl alcohol (PVOH)) were applied by brush to various surfaces of 1 inch XPS foam samples. The application locations of the barrier coating compositions are shown in Table 4 below.

[0096] [Table 4]

[0097] As shown in Table 4 and Figures 4-5, both the EVOH and PVOH coatings were effective at significantly slowing the rate of diffusion of the blowing agent as indicated by the improved R-values ​​and reduced k-values ​​at 180 days compared to the control (Comparative Sample C). In Sample R, the PVOH improved the R-value of the foam sample by approximately 23% compared to the control (Comparative Sample C).

[0098] Example 4 A co-rotating twin-screw single-screw tandem extrusion foam line was used to prepare the extruded polystyrene foam samples. The polystyrene was melted in the extruder and mixed with the injected blowing agent composition to form a homogenous foamable composition. The foamable compositions (excluding blowing agent) of Comparative Samples E-H and Samples T-W contained 100% polystyrene and flame retardant master batch by weight. The foamable compositions of Comparative Samples D and I and Samples X and Y (excluding blowing agent) contained 100% polystyrene, flame retardant master batch, and graphite master batch by weight. The blowing agent blend was included in a constant amount across all samples. The blowing agent blend included fluorinated alkenes and HFCs in a constant ratio of 38 / 62, with the remainder of the blowing agent blend being CO2. As the amount of fluorinated alkenes and HFCs decreased, the amount of CO2 was increased to maintain a constant level of total blowing agent. The foamable composition was then extruded to produce 1 inch XPS foam samples, each having a density of 1.83 pcf.

[0099] For the coated samples, PVOH (aqueous dispersion of polyvinyl alcohol) was applied. The properties of each sample are shown in Table 5 below.

[0100] [Table 5]

[0101] As shown in Figure 6, removal of graphite from the foam composition resulted in an increase in the k factor (Comparative Samples E-H compared to Comparative Sample D), with smaller increases as the amount of fluorinated alkene blowing agent increased. However, the use of a PVOH coating on the foam (Samples T-W) reduced the k factor to an amount below that of the control (Comparative Sample D). As shown in Figure 7, the PVOH coating also provided improved thermal insulation properties for foams containing graphite (Samples X and Y).

[0102] Notably, in Figures 6 and 7, the combination of a PVOH coating with increased levels of fluorinated alkene blowing agent provided the greatest improvement in insulating properties, however Figures 6 and 7 also show that less blowing agent can be used to achieve the same or improved insulating properties.

[0103] Example 5 Various coatings and coating combinations were applied to 1 inch XPS foam samples as shown in Table 6 below. PUD 1 and PUD 2 are two different commercially available polyurethane dispersions. For samples BB and CC, the PVOH coating system was first applied to the foam surface and allowed to dry, then PUD 1 or PUD 2 was applied on top of the PVOH coating.

[0104] [Table 6]

[0105] As shown in Figure 8, PUD 1 and PUD 2 did not provide barrier properties to the foam by themselves (Comparative Samples K and L, respectively). However, when applied on top of an applied PVOH coating (Samples BB and CC, respectively), they enhanced the barrier properties of the PVOH coating (Sample AA). Without wishing to be bound by theory, it is believed that the application of a PUD or hydrophobic coating to a PVOH or EVOH coating, which tend to be more hydrophilic and susceptible to moisture, may protect the hydrophilic coating and enhance the resistance properties of the hydrophilic coating.

[0106] Example 6 DIOFAN® A050 (a PVDC dispersion containing approximately 58% solids by weight commercially available from Solvay) was applied as a barrier coating to various surfaces of 1 inch XPS foam samples using a brush at various coating weights as listed in Table 7 below.

[0107] [Table 7]

[0108] As shown in Table 7 and FIG. 9, the effectiveness of the PVDC coating in significantly slowing the diffusion rate of the blowing agent increased with increasing coating weight, as indicated by the improved R-values ​​and reduced k-values ​​at 180 days compared to the control (Comparative Sample M).

[0109] Example 7 Extruded polystyrene foams containing various blowing agent compositions were prepared and coated with barrier coating compositions to evaluate the effect of the barrier coating on the thermal conductivity properties of the foam. Each foaming composition is shown in Table 8 below.

[0110] [Table 8]

[0111] Samples GG-KK had a barrier coating including DIOFAN® A050 applied to all surfaces of the foam samples, including the edges. Comparative samples N-R were control samples and had no coating applied. Sample LL had a DIOFAN® A050 coating applied to the major surfaces (e.g., top and bottom) but not the edges. Samples MM-OO had the coating applied to the top and bottom and one, two, and three sides, respectively. Sample PP had the coating applied to only four sides. The weights of the foam samples with the barrier coating applied before and after coating are shown in Table 9.

[0112] [Table 9]

[0113] For each of the comparative samples N to R and samples GG to PP, the thermal conductivity was measured on the 7th day (comparative samples N to R and samples GG to LL) or the 8th day (samples MM to PP) (k7), the 20th day (k 20 ), 28th day (k 30 ), 58th day (comparative samples N to Q) or 59th day (comparative samples R and samples GG to PP) (k 60 ), and the 118th day (k 120 ) was measured. k value (Btu in / h ft 2 The predicted R-values ​​at 180 days were calculated based on the regression of the measured thermal conductivities and are also reported in Table 10.

[0114] [Table 10]

[0115] FIG. 10 shows the measured thermal conductivity (k factor) (y-axis) as a function of time in days (x-axis) for samples (both with and without a barrier coating) containing blowing agents containing both 1 wt. % isobutane and 0.25 wt. % isobutane (Comparative Samples N and Q and Samples GG and JJ). As can be seen from Table 10 and FIG. 10, the application of a DIOFAN® A050 coating is effective in reducing the thermal conductivity of the polymeric foam products, such that the polymeric foam products have an R-value of 5 or greater for a longer period of time, as compared to an otherwise identical but uncoated polymeric foam product. In particular, for the samples tested in this example, an R-value of 5 is greater than 0.20 Btu·in / h·ft 2 As shown in Table 10, none of the comparative samples achieved an R-value of 5 at any time. However, each of samples GG-OO achieved an R-value of 5 at k7, and samples GG-II and LL-NN achieved an R-value of 5 at k7. 30 The sample LL achieved an R value of 5 at k 60 An R value of 5 was achieved, which is a significant improvement over the comparative sample.

[0116] Figure 11 shows the measured thermal conductivity (k factor) (y-axis) as a function of time in days (x-axis) for samples (Comparative Sample P and Samples LL-PP) containing 0.50 wt% isobutane and having various surfaces with a barrier coating thereon. As shown in Figure 11, applying a barrier coating to the main surfaces of the polymer foam product has the greatest impact, while coating only the edges has little impact.

[0117] While the present invention has been described with reference to particular means, materials and embodiments, from the foregoing description, those skilled in the art can readily ascertain the essential features of the present invention, and can make various changes and modifications to adapt it to various applications and features without departing from the spirit and scope of the present invention as described above and set forth in the appended claims.

Claims

1. 1. A foamed polymer insulation product comprising:

1. A rigid polymer foam having a first major surface and a second major surface, said polymer foam comprising: a) a thermoplastic matrix polymer composition, wherein the matrix polymer composition is selected from the group consisting of alkenyl aromatic polymers, styrene polymers, styrene copolymers, styrene block copolymers, polyolefins, vinyl halide polymers, polycarbonates, polyesters, polyacrylates, phenolic resins, polysulfones, polyphenylene sulfides, acetal resins, polyamides, polyaramids, polyimides, polyetherimides, rubber-modified polymers, polystyrenes, and combinations thereof; and b) a blowing agent composition comprising a fluorinated blowing agent; a rigid polymer foam formed from a foamable polymer composition comprising: and a barrier coating formed directly on at least one of the first major surface and the second major surface, the barrier coating being effective to stop or slow the rate of diffusion of the blowing agent composition, and formed from a barrier coating composition comprising 20% ​​to 99.9% by weight of at least one polymer selected from polyvinylidene dichloride (PVDC), polyvinylidene fluoride (PVDF), polyvinyl alcohol, ethylene vinyl alcohol, and combinations or copolymers thereof, and 0.1% to 20% by weight of a viscosity modifier.

2. 10. The foamed polymeric insulation product of claim 1, wherein the barrier coating composition further comprises at least one film-forming additive selected from the group consisting of graphene, nanoclay, inorganic layered particles, and combinations thereof.

3. 10. The foamed polymeric insulation product of claim 1, wherein the polymer comprises an aqueous dispersion having a solids content of about 20% to about 60% by weight, based on the total weight of the dispersion.

4. 10. The foamed polymeric insulation product of claim 1, wherein the blowing agent comprises 1,1-difluoroethane (HFC-152a), fluoroethane (HFC-161), fluoromethane (HFC-41), 1,3,3,3-pentafluoropropane (HFO-1234ze), cis-1,1,1,4,4,4-hexafluoro-2-butene (HFO-1336mzz-Z), trans-1,1,1,4,4,4-hexafluoro-2-butene (HFO-1336mzz-E), 1,1,1-trifluoro-3-chloropropene (HCFO-1233zd), 1,1,1,3,3-pentafluorobutane (HFC-365mfc), or combinations thereof.

5. 10. The foamed polymeric insulation product of claim 1, wherein the barrier coating is formed directly on the first major surface and the second major surface of the polymeric foam.

6. 10. The foamed polymeric insulation product of claim 1, wherein the barrier coating is formed directly on at least one minor surface of the polymeric foam.

7. 10. The foamed polymeric insulation product of claim 1, wherein said foamed polymeric insulation product has a thermal resistance value (R-value) of at least 4.75 / inch after 180 days.

8. 1. A method for producing a polymer foam, comprising: a) providing a matrix polymer melt to an extruder, wherein the matrix polymer is selected from the group consisting of alkenyl aromatic polymers, styrene polymers, styrene copolymers, styrene block copolymers, polyolefins, vinyl halide polymers, polycarbonates, polyesters, polyacrylates, phenolic resins, polysulfones, polyphenylene sulfide, acetal resins, polyamides, polyaramids, polyimides, polyetherimides, rubber-modified polymers, polystyrene, and combinations thereof; b) injecting a blowing agent composition comprising a fluorinated blowing agent into the matrix polymer melt in the extruder to form a foamable polymer composition; c) extruding the foamable polymer composition to form a rigid polymer foam having a first major surface and a second major surface; d) directly applying to at least one of the first and second major surfaces of the polymeric foam a barrier coating composition comprising 20% ​​to 99.9% by weight of at least one polymer selected from polyvinylidene dichloride (PVDC), polyvinylidene fluoride (PVDF), polyvinyl alcohol, ethylene vinyl alcohol, and combinations or copolymers thereof, and 0.1% to 20% by weight of a viscosity modifier, wherein the barrier coating composition forms a barrier coating on at least one of the first and second major surfaces of the polymeric foam that is effective to stop or slow the rate of diffusion of the blowing agent composition, thereby forming a coated polymeric foam.

9. 10. The method of claim 8, wherein the coated polymeric foam has a thermal resistance value (R-value) of at least 5.0 / inch after 180 days.

10. 9. The method of claim 8, wherein the blowing agent composition comprises 1,1-difluoroethane (HFC-152a), fluoroethane (HFC-161), fluoromethane (HFC-41), HFO-1234ze-E, HFO-1336mzz-Z, HFO-1336mzz-E, HCFO-1233zd-E, HFC-365mfc, or combinations thereof.

11. 10. The method of claim 8, wherein applying the barrier coating composition comprises applying the barrier coating using a roller, using a brush, or spraying the barrier coating composition directly onto the at least one of the first major surface and the second major surface.

12. the barrier coating is a first barrier coating on the at least one of the first major surface and the second major surface of the polymer foam, and the method comprises:

10. The method of claim 8, further comprising applying a second coating composition to the at least one of the first major surface and the second major surface, wherein the second coating composition forms a second coating on the at least one of the first major surface and the second major surface of the polymeric foam.

13. 13. The method of claim 12, wherein the second coating composition comprises 40% to 99.9% by weight of at least one polymer selected from polyvinylidene dichloride (PVDC), polyvinylidene fluoride (PVDF), polyvinyl alcohol, ethylene vinyl alcohol, and combinations or copolymers thereof, and 0.1% to 20% by weight of a viscosity modifier.

14. The method of claim 12, wherein the second coating composition comprises a dispersion of polyurethane and is applied on top of the first barrier coating.

15. The method of claim 12 , wherein the first barrier coating comprises a dispersion of polyvinylidene dichloride.

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