CN117545902A

CN117545902A - Extruded polystyrene sheet and roof structure containing extruded polystyrene sheet

Info

Publication number: CN117545902A
Application number: CN202280044829.4A
Authority: CN
Inventors: J·罗夫拉诺; V·伍德克拉夫特; B·德沙诺; M·巴杰尔
Original assignee: DuPont Safety and Construction Inc; DDP Specialty Electronic Materials US LLC
Current assignee: DuPont Safety and Construction Inc; DDP Specialty Electronic Materials US LLC
Priority date: 2021-06-24
Filing date: 2022-06-21
Publication date: 2024-02-09
Also published as: US20230405979A1

Abstract

An Inverted Roof Membrane Assembly (IRMA) includes a floor deck, a waterproofing membrane above the floor deck, a polymer foam insulation slab layer above the waterproofing membrane, and ballast above the polymer foam insulation slab layer. The polymeric foam insulation panel includes a polymeric foam layer comprising an alkenyl aromatic polymer and an infrared radiation attenuating agent, and a first facing layer and a second facing layer.

Description

Extruded polystyrene sheet and roof structure containing extruded polystyrene sheet

Background

The present invention relates to extruded polystyrene sheets and roof structures comprising extruded polystyrene sheet layers, in particular Inverted Roof Membrane Assemblies (IRMA), also known as "protective membrane roofs" (PMR).

The low-slope roof is generally constructed by installing insulation layers on the floor carrier plates and installing waterproof membranes on the insulation layers. Although this type of construction is widely used, it has significant problems because the film is exposed to various weather and significant seasonal and daily thermal cycling. The film is subject to physical damage (e.g., puncture, debris fall, hail, ice fall, icing), damaging electromagnetic radiation (UV, visible, infrared, etc.), chemical attack (e.g., from atmospheric contaminants such as ozone, sulfur dioxide, acid rain, bird droppings, etc.), and large temperature fluctuations. All of this can damage the exposed film, shorten its useful life, and require frequent maintenance.

Many of these problems are addressed by so-called Inverted Roof Membrane Assemblies (IRMA). In IRMA, the insulation layer is applied over the membrane rather than under the membrane. The membrane is protected from most potential damage causes and therefore has a longer service life and requires less maintenance and less maintenance. IRMA can support a conventional low-slope membrane roof for twice or three times as long if properly maintained. Another advantage of IRMA is that they can be used as part of so-called "green roof" and "blue roof" systems, where vegetation and stagnant water are located on top of the roof assembly.

Extruded polystyrene (XPS) foam is a good candidate for insulation in IRMA because it has a combination of good mechanical properties, good insulation value, water penetration resistance and low cost. XPS foam is manufactured as a sheet that is easy to install and fits a specific roof geometry.

Building codes in many jurisdictions are being modified to require increased roof insulation values. This can in principle be achieved by making the insulation layer thicker, since the insulation value generally increases with the thickness. However, there are practical constraints to do so; in general, other structures require vertical space and in the event of roof replacement, the surrounding structure (retaining wall, wall height, etc.) may not allow for too much increased insulation thickness, if any. Thicker insulation also means higher project costs.

Of course, if the thermal resistivity or RSI value is high, a thinner insulating layer may be used. XPS can generally have up to about 1 K.m ² RSI value/W/25.4 mm thickness. If the RSI value is high, a thinner XPS insulating layer may be used. One way to achieve this is to incorporate an infrared attenuator such as graphite or carbon black into the XPS foam. However, some XPS insulation materials containing infrared attenuation agents have been found to warp easily when exposed to sunlight during installation.

Disclosure of Invention

One aspect of the present invention is a polymeric foam insulation panel comprising a foamed polymer layer comprising one or more organic polymers comprising at least 70% by weight of one or more alkenyl-aromatic polymers, the foamed polymer layer having opposed first and second major surfaces and a thickness orthogonal to the opposed major surfaces; a first facing sealingly bonded to the first major surface to form a first outer surface; and a second facing sealingly bonded to the second major surface to form a second outer surface, wherein:

the foamed polymer layer has a weight of at most 56kg/m ³ (3.5 lbs/cfm) foam density, a thickness of at least 0.6cm (0.25 in.), a thickness of at least 0.95 K.m ² RSI value of/W/25.4 mm thickness (5.11 F.ft) ² An R value of h/BTU/inch thickness) and contains at least 0.25 weight percent of an infrared radiation attenuating additive based on the weight of the foamed polymer layer；

The first facing layer has an opacity of at least 65% and at most 0.65cc/m ² Oxygen transport rate (oxygen transmission) per day of at most 0.9 cc-mil/m ² -an oxygen permeability in days and an elmendorf tear strength (Elmendorf tear strength) of at least 120g/25.4 μm in at least one direction;

the second facing layer has a bulk of at most 0.65cc/m ² Oxygen transport rate up to 0.9 cc-mil/m per day ² -oxygen permeability in days and elmendorf tear strength of at least 120g/25.4 μm in at least one direction, and

the first outer surface exhibits a surface solar reflectance of at least 35% as measured according to ASTM C1549.

The invention also relates to an inverted roof membrane assembly comprising:

A. floor support plate;

B. a waterproof membrane mounted directly or indirectly on top of the floor support plate; and

C. at least one layer of the polymeric foam insulation panel of the present invention directly or indirectly on top of layer B; and

D. a ballast layer directly or indirectly on top of layer C.

Drawings

Fig. 1 is a partial cutaway isometric view of an embodiment of an inverted roof membrane assembly of the invention.

Fig. 2 is a cross-sectional side view of a polymer foam insulation panel of the present invention.

Fig. 3 is a cross-sectional side view of an embodiment of a facing for use in the present invention.

Detailed Description

Referring back to fig. 1 and 2, the inverted roof membrane assembly 11 includes a floor support plate 9, a waterproofing membrane 8 mounted atop the floor support plate 9, a polymeric foam insulation panel 1 mounted atop the waterproofing membrane 8, an optional filter fabric 12 mounted atop the polymeric foam insulation panel 1, and ballast 10 mounted atop the filter fabric 12. The polymeric foam insulation panel 1 includes a foamed polymer layer 2, a first facing layer 3, and a second facing layer 4. The first facing 3 creates a first outer surface 18 of the polymeric foam insulation panel 1 and the second facing 4 creates a second outer surface 19 of the polymeric foam insulation panel 1. For ease of illustration, the dimensions of the various materials shown in FIG. 1 are not to scale. Specifically, the thicknesses of the first and second facings 3, 4 are exaggerated.

When used for roof or other generally horizontal installations, the first and second facings 3, 4 are conveniently considered to be "top" and "bottom" facings, respectively. Similarly, the first outer surface 18 and the second outer surface 19 of the polymer foam insulation panel 1 are in this case conveniently considered to be "top" and "bottom" surfaces, respectively. "top" and "bottom", when used with respect to a facing or outer surface, refer to the orientation of the polymeric foam insulation panel 1 when installed (as in an inverted roof membrane assembly installation). The first or "top" facing means the facing that faces outwardly when installed, i.e., away from the structure to which it is applied and generally toward the exterior of the building; in an inverted roof structure, a first or "top" facing layer forms the outermost surface of the polymeric foam insulation panel. When installed in a roof structure, the second or "bottom" facing layer 4 is on the side of the polymeric foam insulation board 1 facing the membrane 8 and the floor deck 9, while the first or "top" facing layer 3 is on the opposite side of the polymeric foam insulation board 1 facing the ballast and the exposed roof surface and forming the outermost surface of the polymeric foam insulation board.

The foamed polymer layer 2 comprises one or more organic polymers comprising one or more alkenyl-aromatic polymers. By "alkenyl-aromatic polymer" it is meant a homopolymer of alkenyl-aromatic monomers, a copolymer of two or more alkenyl-aromatic monomers, or a polymer (e.g., random, block, and/or graft copolymer) of at least 50 wt.%, preferably at least 70 wt.%, or at least 75 wt.% of one or more alkenyl-aryl monomers with up to 50 wt.%, preferably up to 30 wt.%, or up to 25 wt.% of one or more other monomers that are not alkenyl-aromatic monomers.

Alkenyl-aromatic monomers include, for example, styrene, alpha-methylstyrene, ethylstyrene, vinyltoluene, chlorostyrene, and bromostyrene.

Examples of other monomers include, for example, 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.

Alkenyl aromatic polymers are thermoplastic and may be linear or branched. The alkenyl aromatic polymer may have a weight average molecular weight of at least 40,000g/mol, at least 60,000g/mol, or at least 75,000g/mol as measured by Gel Permeation Chromatography (GPC) against polystyrene standards. By GPC against linear polystyrene standards, it may have a weight average molecular weight of, for example, up to 500,000g/mol, up to 300,00g/mol, up to 250,000g/mol or up to 150,000 g/mol. The alkenyl aromatic polymer may have a polydispersity (weight average molecular weight/(number average molecular weight) of 1 to 3 or more, preferably 1 to 2.5.

In some embodiments, water is soluble in the alkenyl aromatic polymer at 130 ℃ and 101kPa pressure to a degree of 0.09 to 2.2 moles water per kg alkenyl aromatic polymer (mol/kg), preferably 0.15 to 2.2 moles/kg.

Particularly interesting alkenyl aromatic polymers are styrene homopolymers and random and/or block copolymers of styrene and acrylonitrile. Particularly preferred alkenyl aromatic polymers are random and/or block copolymers containing 0.1 to 30 weight percent polymerized acrylonitrile, 70 to 99.9 weight percent polymerized styrene, and 0 to 2 weight percent of one or more other monomers, such as other alkenyl aromatic monomers. Such styrene-acrylonitrile copolymers may contain, for example, at least 5% by weight or at least 10% by weight of polymerized acrylonitrile, and may contain up to 25% by weight, up to 22.5% by weight or up to 20% by weight of polymerized acrylonitrile. Such styrene-acrylonitrile copolymers may exhibit a positive "deviation" and/or a positive percentage difference between the average and median copolymerized acrylonitrile distributions, each as defined in U.S. patent No. 8,324,287 (incorporated by reference), and may alternatively or additionally have an average copolymerized acrylonitrile content of 20 weight-% or less.

The one or more alkenyl aromatic polymers preferably contain no more than 20 weight percent halogen, more preferably no more than 10 weight percent halogen or no more than 5 weight percent halogen. They may contain any lesser amount of halogen and may be halogen-free.

More than one alkenyl aromatic polymer may be present. In addition, the organic polymer may comprise one or more other organic polymers that are not alkenyl aromatic polymers. Such other organic polymers, if present, are preferably no more than 15 percent, more preferably no more than 5 weight percent, based on the total weight of all organic polymers. Other organic polymers may be more hydrophilic than one or more alkenyl aromatic polymers. For example, water can be soluble in other organic polymers in amounts greater than 2.2 moles/kg at 130 ℃ and 101kPa pressure. Examples of such other organic polymers include ethylene with acrylic acid, methacrylic acid, C _1-4 Copolymers of one or more of polycarboxylic acid and/or acrylate monomers; polyvinyl acetate; and polyacrylonitrile.

The foamed polymer layer includes at least 0.25 weight percent, at least 0.5 weight percent, or at least 1.0 weight percent of one or more infrared attenuating additives, i.e., additives that inhibit the transmission of infrared radiation through the polymer foam, based on the weight of the foamed polymer layer. The foamed polymer layer may contain, for example, up to 5 weight percent, up to 3 weight percent, or up to 2 weight percent of one or more infrared attenuating additives. Among the useful infrared absorbing additives are various forms of carbon (including, for example, one or more of graphite, carbon black, soot, carbon fibers, flakes or powders, carbon nanotubes and fullerenes, powdered amorphous carbon, etc.), metal flakes, metal and semi-metal oxides such as titanium dioxide, silicon dioxide, manganese (IV) oxide, magnesium oxide, bismuth (III) oxide, cobalt oxide, zirconium (IV) oxide, molybdenum (II) oxide, calcium oxide, and aluminum boehmite. Preferred polymer layers contain 0.25 to 5, preferably 0.25 to 3 weight percent of one or more forms of carbon, especially graphite, carbon black or mixtures thereof.

The polymer foam layer comprises gas-containing cells. In some embodiments, the gas in the cells comprises at least one fluorocarbon having 1 to 4 carbon atoms. In some embodiments, the fluorocarbon is chlorine-free. 1, 3-tetrafluoropropene (1234 ze), 1, 3-tetrafluoropropene, 2, 3-tetrafluoropropene (1234 yf) 1,2, 3-pentafluoropropene (1225 ye), 1-trifluoropropene, 1, 3-pentafluoropropene (1225 zc) 1, 3-tetrafluoropropene (1234 ze), 1, 3-tetrafluoropropene, 2, 3-tetrafluoropropene (1234 yf), 1,2, 3-pentafluoropropene (1225 ye), 1-trifluoropropene, 1, 3-pentafluoropropene (1225 zc), and 1,2, 3-pentafluoropropene (1225 yc), (Z) -1, 2, 3-pentafluoropropene (1225 yez), 1-chloro-3, 3-trifluoropropene (1233 zd) and 1, 4-hexafluorobut-2-ene (1336 mzzm), and other Hydrofluoroolefin (HFO) and/or Hydrochlorofluoroolefin (HFCO) blowing agents, such as those described, for example, in US 2007/0100010.

In some embodiments, the gas in the cells comprises carbon dioxide; water; and/or one or more C _1-9 And (3) hydrocarbons. In a preferred embodiment, the gas in the cells comprises at least one fluorocarbon, carbon dioxide, water, and optionally also at least one hydrocarbon.

The density of the foam layer is at most 56kg/m ³ (3.5 pounds per cubic foot (pcf)). The foam layer density may be at least 21kg/m ³ (1.3 pcf), at least 28kg/m ³ (1.75 pcf) or at least 32kg/m ³ (2 pcf); and may be up to 40kg/m in some embodiments ³ (2.5 pcf) or up to 56kg/m ³ (3.5pcf)。

The polymeric foam layer may contain other materials that perform useful functions in the foam layer and/or in preparing the foam layer. Examples of such other materials include, for example, pigments (other than one or more infrared attenuating additives), fillers, antioxidants, extrusion aids, cell nucleating agents (other than one or more infrared attenuating additives), antistatic agents, flame retardants and/or smoke suppressants, acid scavengers, and the like.

The foam layer has a thickness of at least 0.6cm (0.25 inches). The foam layer thickness may be any greater value, such as up to 45.7cm (18 inches), up to 30.5cm (12 inches), up to 20.3cm (8 inches), or up to 15.24cm (6 inches). An advantage of the present invention is that the relatively thin foam layer provides excellent thermal insulation due to the high RSI value of the foam. Particularly preferred thicknesses are at least 7.62cm (3 inches) or at least 10.16cm (4 inches) and up to 20.3cm (8 inches) or up to 15.24cm (6 inches).

The foam layer has a composition of at least 0.95 K.m as measured according to ASTM C518-17 at an average temperature of 24 DEG C ² RSI value/W/25.4 mm thickness. The foam layer may have an RSI value of at least 1.0, at least 1.05, at least 1.1, at least 1.25, or at least 1.4K-m ² W/25.4mm thickness. In some embodiments, the RSI value is up to 2, up to 1.75, up to 1.6, or up to 1.5 K.m ² W/25.4mm thickness.

The foam layer is preferably an extruded foam made by: forming a pressurized mixture of one or more heat softened alkenyl aromatic polymers, one or more blowing agents, one or more infrared absorbing additives, and other optional ingredients, if any, and then exposing the pressurized mixture to lower pressure and temperature such that the mixture expands and cools to form a cellular foam. Such extrusion processes are well known and are described, for example, in U.S. Pat. nos. 5,380,767, 8,324,287 and 9,051,438, and many other references. The extrusion process is conveniently carried out using a single screw or twin screw extruder to form a pressurised mixture which exits the extruder through a die (typically a dog bone die) after which the mixture is expanded and cooled. Cumulative extrusion processes as described in U.S. published patent application No. 2008-0139582A are also useful.

The gas within the cells of the resulting polymer foam corresponds, at least initially, to the blowing agent used to make the foam. Thus, the blowing agent may comprise, for example, one or more fluorocarbons having 1 to 4 carbon atoms as described above; carbon dioxide; water; and C _1-9 And (3) hydrocarbons. In some embodiments, the blowing agent is a mixture comprising a fluorocarbon having 1 to 4 carbon atoms; carbon dioxide and water; in such a mixture, the fluorocarbonThe compounds may be provided, for example, in an amount of from 0.4 to 2, especially from 0.5 to 1.2, mol/kg of one or more alkenyl aromatic polymers (mol/kg); carbon dioxide may be provided, for example, in an amount of from 0.1 to 0.5, in particular from 0.2 to 0.4, mol/kg; and water may be provided, for example, in an amount of 0.15 to 2, especially 0.25 to 1.5mol/kg, wherein the total amount of blowing agent is 0.65 to 2.5mol/kg. Such a blowing agent mixture is described, for example, in US 2008/140892.

The first facing 3 is sealingly bonded to one major surface of the polymer foam layer 4 and the second facing 4 is sealingly bonded to the opposite major surface of the polymer foam layer 2. By "sealingly bonded" it is meant that the facing layer is bonded to the polymer foam layer in such a way that a mechanical barrier to the overall transfer of gas into and out of the major surface of the polymer foam layer to which the facing layer is applied is formed. Thus, gas transport (if any) through the major surface must occur through permeation of one or more gases through the facing layer. Thus, the facing layer is preferably continuous, free of holes and other openings, and covers substantially the entire major surface to which it is applied. The bond strength between each facing and the polymer foam layer should be at least 150 grams force/25.4 cm as measured using an instron universal tester running at a crosshead speed of 250 mm/min and tested at 23 ℃ and 50% Relative Humidity (RH). The facing layer may be directly bonded to the polymer foam layer. Alternatively, the facing layer may be bonded to the polymer foam layer by an adhesive layer.

Each facing takes the form of one or more film layers. When the facing layer is comprised of two or more film layers, those layers may be applied separately to the polymer foam layer. Some or all of these individual layers may be assembled into a multilayer structure first, which is then applied to the polymer foam. The facing layer is preferably thermoplastic.

The first facing has an opacity of at least 65% as measured by ASTM D1003-13. The opacity may be at least 70% or at least 75% and up to 100%. The first facing surface of the polymeric foam insulation panel also preferably exhibits a surface solar reflectance of at least 35%, at least 40%, or at least 50% as measured according to ASTM C1549 after lamination. The surface solar reflectance may be any higher value up to 100%. The second facing may or may not exhibit one or both of these characteristics. In some embodiments, the second facing meets both the opacity and solar reflectance requirements of the first facing, and may even be the same material as the first facing. Such an embodiment is advantageous from an installation perspective, because either major surface of the polymeric foam insulation panel may be installed face up (or outward). When the second facing lacks these opacity and reflectance characteristics, the polymeric foam insulation panel should be installed with the first facing up or out.

Both facings exhibit oxygen barrier properties. The facing layer exhibits a surface layer of at most 0.65cc/m as measured at 23 ℃ according to ASTM D3985-17 ² Oxygen transport rate (oxygen transmission) per day and at most 0.9 cc-mil/m ² Oxygen permeability in days.

Each facing layer should exhibit an Elmendorf tear strength of at least 120 g/mil thickness (120 g/25.4 μm thickness) in at least one direction as measured according to ASTM D1922-15 at 23℃and 50% RH.

Each facing layer preferably comprises at least one oxygen barrier polymer layer (reference numeral 5 in fig. 3). The oxygen barrier polymer layer 5 itself may exhibit up to 0.9, up to 0.5, or up to 0.3 cc-mil/m as measured according to ASTM D3985-17 ² Oxygen permeability in days. The oxygen barrier polymer layer may have a thickness of, for example, 1.27 to 50.8 μm (0.05 to 2 mils), preferably 2.54 to 50.8 μm (0.1 to 2 mils), or 5.08 to 38.1 μm (0.2 to 1.5 mils). Such thicknesses are generally sufficient to reduce the substitution of oxygen or air for the blowing agent in the cells of the polymer foam layer, thereby maintaining the thermal conductivity of the polymer foam layer at a low value over a long period of time.

Examples of useful oxygen barrier polymers include ethylene vinyl alcohol copolymers, vinylidene chloride polymers and copolymers, and polyamides. Ethylene vinyl alcohol polymers are particularly suitable. The ethylene-vinyl alcohol polymers may contain, for example, from 10 to 50mol-%, in particular from 15 to 35mol-% of ethylene units and correspondingly from 50 to 90mol-%, in particular from 65 to 85mol-% of vinyl alcohol units, the ethylene and vinyl alcohol units preferably being distributed randomly. Ethylene vinyl alcohol polymers can be prepared by polymerizing a monomer mixture of ethylene and vinyl acetate, followed by hydrolysis of the acetate groups to produce vinyl alcohol repeating units.

Each facing layer preferably includes at least one moisture barrier (as shown by reference numerals 6, 7 in fig. 3). One or more moisture barriers may be present directly or indirectly on either side of the oxygen barrier polymer layer 5. Each moisture barrier suitably exhibits a moisture barrier of no more than 47g/M at 38 ℃ (ASTM E96/E96M-16) ² Day (3.0 g/100 inch) ² Day) permeability to water. The moisture barrier may have a thickness of, for example, 1.27 to 50.8 μm (0.05 to 2 mils), especially 2.54 to 25.4 μm (0.1 to 1 mil), or 2.54 to 12.7 μm (0.1 to 0.5 mils).

In some embodiments, the moisture barrier comprises a thermoplastic polymer that provides moisture barrier properties. Suitable thermoplastic polymers include, for example, polyethylene (including any one or more of low density polyethylene, linear low density polyethylene, high density polyethylene, metallocene polyethylene), polypropylene homopolymers, copolymers of propylene and ethylene, ethylene-vinyl acetate polymers, and the like. Blends of two or more such polymers may be used.

In addition to the thermoplastic polymer, the moisture barriers 6, 7 may each independently comprise various ingredients such as antioxidants, film processing aids (e.g., slip agents, etc.), pigments, dyes, and/or other colorants, etc. The moisture barrier in the first facing layer 3, in particular the moisture barrier 6 in fig. 3, preferably comprises at least one reflective filler. The reflective filler is a material that itself reflects at least 80% of incident visible light (i.e., incident light having a wavelength of 400 to 700 nm). The reflective filler preferably also absorbs, scatters or reflects ultraviolet light, in particular both UVA and UVB radiation. Titanium dioxide and calcium carbonate are particularly suitable reflective fillers.

The moisture barrier may also contain one or more ultraviolet light absorbers that are not reflective fillers. Such ultraviolet light absorbers may include, for example, benzophenone and various aryl esters, benzotriazoles, and formamidines.

The first or second facing layer may also include one or more adhesive layers (15, 16 in fig. 3) that promote adhesion between the various layers, particularly between the moisture barrier and the oxygen barrier polymer layers. The tie layer may be, for example, a polyolefin, particularly polyethylene, modified with a functional group such as a carboxylic acid or carboxylic acid anhydride. The tie layer may have a thickness of, for example, 1.27 to 25.4 μm (0.05 to 1 mil), especially 2.54 to 12.7 μm (0.1 to 0.5 mil).

In one particular embodiment, the first facing layer may include an inner (i.e., facing the polymer foam layer) moisture barrier 7 (fig. 3) comprising an ethylene vinyl acetate polymer (which may itself be a multi-layer structure); an oxygen barrier polymer 5 layer comprising an ethylene-vinyl alcohol copolymer; and an outer (i.e., facing away from the polymer foam layer) moisture barrier layer 6 comprising polyethylene (including any one or more of low density polyethylene, linear low density polyethylene, high density polyethylene, metallocene polyethylene). The outer moisture barrier 6 preferably comprises at least one reflective filler, at least one ultraviolet light absorber, or both reflective filler and ultraviolet light absorber.

In another specific embodiment, the second facing layer may comprise an inner (i.e. facing the polymer foam layer) moisture barrier 7 (which may itself be a multilayer structure) comprising an ethylene vinyl acetate polymer; an oxygen barrier polymer layer 5 comprising an ethylene-vinyl alcohol copolymer; and an outer (i.e., facing away from the polymer foam layer) moisture barrier layer 6 comprising polyethylene (including any one or more of low density polyethylene, linear low density polyethylene, high density polyethylene, metallocene polyethylene). The outer moisture barrier 6 of such a second facing layer may or may not comprise at least one reflective filler, at least one ultraviolet light absorber, or both reflective filler and ultraviolet light absorber; however, as previously mentioned, it is often convenient to use the same material as both the first and second facings, in which case the outer moisture barrier 6 may contain reflective fillers, ultraviolet light absorbers, or both.

The total thickness of the first or second facing layer may be, for example, 1.27 to 127 μm (0.5 to 5 mils), especially 19.05 to 63.5 μm (0.75 to 2 mils), or 25.4 to 50.8 μm (1 to 2 mils).

The polymeric foam insulation panels of the present invention are conveniently provided in the form of rectangular or square panels having a length (longest dimension) of from 0.61 meters (24 inches) to 3.66 meters (12 feet), especially from 1.83 to 3.66 meters (6 to 12 feet), and a width (orthogonal to the length along the major surface) of from 0.305 meters (12 inches) to 3.66 meters (12 feet), especially from 0.46 meters (18 inches) to 2.44 meters (8 feet), or from 0.61 meters (2 feet) to 1.83 meters (6 feet).

The polymeric foam insulation panel may be notched-bonded along one or more edges (preferably all four edges) to facilitate mating with adjacent portions of the polymeric foam insulation panel during installation.

The floor support 9 is a load bearing layer supporting the overlying structure. It may have concrete, reinforced concrete, metal, wood, composite materials, organic polymers or other building materials capable of withstanding the superimposed weight.

The waterproofing membrane 8 is typically a thermoplastic or thermoset rubber such as a thermoplastic olefin, an ethylene-propylene-diene terpolymer, or polyvinyl chloride. Asphalt rubber membranes, such as modified asphalt styrene-butadiene-styrene rubber membranes, are also useful. The asphalt rubber membrane may be reinforced with glass and/or polymer fibers. The waterproofing membrane 8 may have a thickness of, for example, 254 μm to 2.54mm (10 to 1000 mils), especially a density of 635 to 6350 μm (25 to 250 mils) or 635 to 3810 μm (25 to 150 mils). The waterproofing membrane 8 may comprise a plurality of layers.

As shown in fig. 1, in IRMA, the waterproofing membrane 8 may be mounted directly above the floor support plate 9. Alternatively, one or more optional layers may be installed between the floor support plate 9 and the waterproofing membrane 8. Examples of such optional layers may include, for example, drainage or raft sheet good layers. Such layers may comprise, for example, semi-porous fabrics, the function of which is to facilitate the flow of water into one or more drainage structures through which water may be removed from the roof structure. Such semi-porous fabric may be, for example, a geotextile such as a American national Highway and transportation officials Association grade 1or grade 2 (American Association of State Highway and Transportation Officials Class or Class 2) geotextile. One example of a suitable geotextile is one having a weight of 50 to 500g/m ² Polypropylene fabrics, e.g. asThe separating fabric is commercially available. Another suitable layer is a dimpled sheet or fabric, wherein water is collected in the dimples. Such dimpled sheets are sometimes referred to as "egg box" structures and may be designed with openings through which excess water may flow to lower layers or out through a drainage system when the dimples are filled.

Similarly, if desired, one or more of the optional layers just described may be installed in the IRMA between the waterproofing membrane 8 and one or more layers of the polymeric foam insulation panel 3.

When the IRMA is assembled, the layer of polymeric foam insulation panel 3 may be installed in the same manner as a conventional foam insulation panel by: the various portions of the sheet material are laid adjacent to each other to cover the waterproofing membrane 8 and form a thermally insulating and protective structure over the waterproofing membrane 8. When the slots are engaged, the various portions of the sheet material may be mated to form a slot joint between adjacent sheet material portions. Adjacent sheet portions may be shiplap or even interlocked by a corresponding mating notch on each adjacent sheet portion. Forming a channel between the first outer surfaces of adjacent sheet material portions when the ship lap joint is performed; these channels may act to direct water towards the drain or roof edge.

The polymer foam insulation sheet layers may or may not be secured to the underlying roof structure. Optionally, it may be secured by the use of an adhesive or by any suitable mechanical fastening method. Alternatively or in addition, the polymeric foam insulation slabs are at least partially loosely laid and at least partially held in place by and covered with ballast material (i.e., dense, heavy material that holds the polymeric foam insulation slabs in place by gravity). The ballast material may comprise coarse or fine particulate material such as gravel, stones or soil. The ballast may be or include a planting medium for a green roof or other green roof structure or component of a green roof structure. The ballast may be or include a blue roof structure or a component thereof. Other ballast materials include paving materials of various shapes and sizes, which may form continuous or discontinuous layers. Different ballast materials may be used in any particular roof structure of the present invention.

Other optional components of the inverted roof membrane assembly may include, for example, one or more hydrophilic foam layers; one or more filter fabric, drainage or raft sheet good layers; one or more vegetation growing medium layers, if not part or all of the ballast; one or more vegetation layers; one or more root barriers; one or more separating fabrics for preventing vegetation growing medium from scouring down to the lower layer while allowing water to pass through; various components of the drainage system, such as one or more drain pipes, tubes, tanks or other fluid conduits, and associated flow management devices, such as plugs, valves, pumps, flow control systems, etc.; one or more water accumulation mechanisms for capturing and retaining water, if not part or all of the ballast, any or all of which may be present directly or indirectly on the polymer foam insulation slab 3. The inverted roof membrane assembly may be a "green roof" with a vegetation layer, a "blue roof" that provides for the initial temporary retention of water (typically rainfall or other precipitation) rather than through the vegetation layer and then gradual release of the stored water, and/or a "blue-green" or "green-blue" roof that combines the features of both green and blue roofs.

While the polymeric foam insulation panel of the present invention is particularly useful in roofing applications, particularly in IRMA, it can also be used in other insulation and/or protection applications in substantially the same manner as conventional insulation panels. Examples of such other uses include, for example, thermally insulated concrete forms; floor insulation, including insulation to heat the floor; an insulated concrete tilt wall; heat insulating underground masonry structures such as basement walls and/or floors; structural insulating panels; insulation of conventional (i.e., non-inverted) low-grade roofs; insulation for a spa and/or a hot water bathtub, including spa hot water bathtub covers; insulation for refrigerated vehicles such as trucks and rail cars; insulation for geothermal applications; HVAC insulation; the built-in or independent refrigerator and/or freezer insulates against heat; thermal insulation of pavements such as sidewalks, roads, runways, and parking lots; protecting frozen soil; a heat-insulating power transmission tower base; etc.

In those other applications where the polymeric foam insulation panel is exposed to incident radiation (particularly visible, UV and/or infrared radiation), the polymeric foam insulation panel is preferably mounted with a first exterior (or "top") surface facing the incident radiation and a second exterior (or "bottom") surface facing the structure to which the polymeric foam insulation panel is applied. In applications where exposure of the polymeric foam insulation panel to incident radiation is not desired, either the first outer surface or the second outer surface may be oriented away from the underlying structure to which the polymeric foam insulation panel is attached.

As previously mentioned, in these applications, the polymeric foam insulation panel layer may be installed in the same manner as a conventional foam insulation panel by: the various portions of the sheet material are laid adjacent to one another to form a thermally insulating and protective layer over the underlying structure. When the slots are engaged, the various portions of the sheet material may be mated to form a slot joint and/or other interlocking joint between adjacent sheet material portions. Furthermore, as previously mentioned, the boat-shaped overlap channel between the first outer surfaces of adjacent sheet material portions may function to direct water toward the edges of the gutters or sheet material layers.

Examples

Among other advantages, the first and second facing layers provide excellent moisture resistance to the polymer foam insulation panels of the present invention. To evaluate this, extruded polymer foams were prepared in the general manner described in column 10 of U.S. patent No. 8,324,287, 4.0 parts by weight per 100 parts by weight of polymeric carbon black was added, and then immediately laminated to the first and second facing layers as described below. The polymer is a styrene-acrylonitrile resin containing 15-20 wt% polymerized acrylonitrile, having a weight average molecular weight of 125,000 to 150,000g/mol and a polydispersity of 2.25 to 2.4 and also having a positive "bias" of about 0.9. Although thicker foam will typically be used in the inverted roof membrane assemblies of the present invention, for the purpose of evaluating moisture resistance, a foam having a thickness of 1.7cm, a width of 35cm and a density of 33.3kg/m was prepared ³ Is a plate material of the (c).

The multilayer facing is prepared by coextrusion. For this experiment, the first and second facings were identical. Each facing layer comprises, in order from the inside (beside the foam layer) to the outside, the following layers, reference numbers referring to fig. 3:

layer 7: ethylene-vinyl acetate (25 wt. -% vinyl acetate) copolymer 74-76 wt. -%) and low density polyethylene (22 wt. -%) with a small amount of film processing aid. Layer 7 had a thickness of 11.81 μm (0.465 mil).

Layers 15 and 16. A tie layer, which is a blend of linear oligomer (85 wt. -%) with anhydride modified polyethylene (15 wt. -%). The thickness was 6.86 μm (0.27 mil) and 3.05 μm (0.12 mil), respectively.

Layer 5. Ethylene-vinyl alcohol copolymer (15-35 wt. -% vinyl alcohol units) between tie layers C and E. The thickness was 6.86 μm (0.27 mil).

Layer 6. Low density polyethylene with benzophenone, titanium dioxide and antioxidants, and small amounts of film processing aids. The thickness was 9.53 μm (0.375 mil).

Each facing layer has an opacity of at least 65% and at most 0.65cc/m ² Oxygen transport rate up to 0.9 cc-mil/m per day ² -a daily oxygen permeability and an elmendorf tear strength in machine direction of at least 120 g/mil. The width of the facing layer was 40cm. Each facing layer exhibits a surface reflectance of at least 35% after lamination to the foam substrate.

The first and second facing layers were laminated to the major surface of the foamed polymer using a twin heated roll laminator set at 190 c, located about 5 meters downstream of the foam extrusion die. The lamination pressure was 40psi (276 kPa) and the line speed was about 7 meters/minute. The apparent density of the laminate product was 33.3kg/m ³ 。

The laminated foam was then immersed in DI water at 21 ℃ for two months at a water head of 2.5 cm. After two months, the laminated foam absorbed 0.01vol% of water. Without the facing layer, the same polymer foam absorbed about 0.5vol% of water under similar test conditions.

According to ASTM C518,the thermal conductivity of the laminated foam was measured before and after flooding using an average temperature of 10 ℃ and 24 ℃. At a test temperature of 10 ℃, the laminated foam exhibited 1.153 k.m before immersion ² RSI value of/W/25.4 mm thickness (6.55 F.ft) ² An R value of h/BTU/inch thickness) and exhibits 1.051 K.m after immersion ² RSI value/W/25.4 mm thickness (R value/inch 5.97), or loss of less than 9%. At 24℃test temperature, the laminated foam exhibited 1.071 K.m before immersion ² RSI value of/W/25.4 mm thickness (R value/inch is 6.08), and shows 0.983 K.m after immersion ² RSI value/W/25.4 mm thickness (R value/inch 5.58), or losses slightly greater than 8%.

A second extruded polymeric foam was prepared in the general manner described in column 10 of us patent No. 8,324,287, wherein the blowing agent package had a low global warming potential and 1.0 parts by weight per 100 parts by weight of polymeric graphite (Hubron international grade graphite PSB 5) was added and then immediately laminated to the first and second facing layers as described above. The foamed polymer is a styrene-acrylonitrile resin containing 15-20 wt% polymerized acrylonitrile, having a weight average molecular weight of 125,000 to 150,000g/mol and a polydispersity of 2.25 to 2.4 and also having a positive "bias" of about 0.9. The foamer package contained 4.25pph HFC152a, 4.25pph HFO1234ze, 0.9pph CO ₂ And 0.9pph H ₂ O. The foam sheet had a thickness of 1.5cm, a width of 33cm and a density of 22.4kg/m ³ . The adhesive strength between the foam core and the facing was 1.47N/25.4mm (150 grams force/inch). The RSI was 1.18 (R6.7/inch) compared to the RSI of 0.97 (R5.5/inch) for the baseline sample (unobstructed facing).

Claims

1. A polymeric foam insulation panel comprising a foamed polymer layer comprising one or more organic polymers comprising at least 70% by weight of one or more alkenyl-aromatic polymers, the foamed polymer layer having opposed first and second major surfaces and a thickness orthogonal to the opposed major surfaces; a first facing sealingly bonded to the first major surface to form a first outer surface; and a second facing sealingly bonded to the second major surface to form a second outer surface, wherein:

the foamed polymer layer has a weight of at most 56kg/m ³ (3.5 lbs/cfm) foam density, a thickness of at least 0.6cm (0.25 in.), a thickness of at least 0.95 K.m ² RSI value of/W/25.4 mm thickness (5.11 F.ft) ² An R value of h/BTU/inch thickness) and contains at least 0.25 weight percent of an infrared radiation attenuating additive based on the weight of the foamed polymer layer;

the first facing layer has an opacity of at least 65% and at most 0.65cc/m ² Oxygen transport rate up to 0.9 cc-mil/m per day ² -a daily oxygen permeability and an elmendorf tear strength of at least 120g/25.4 μm in at least one direction;

2. The polymeric foam insulation panel of claim 1, wherein said foamed polymer layer has a weight of 21 to 56kg/m ³ And a foam density of 7.62 to 15.24 cm.

3. The polymeric foam insulation panel of claim 1or 2, wherein the alkenyl-aromatic polymer is a styrene-acrylonitrile copolymer containing 10 to 22.5 weight percent polymerized acrylonitrile and no more than 5 weight percent halogen based on the weight of the styrene-acrylonitrile copolymer.

4. The polymeric foam insulation panel of any one of claims 1-3, wherein the foamed polymer layer contains 0.25 to 5 weight percent of an infrared radiation attenuating agent, and the infrared radiation attenuating agent is one or more of: graphite; carbon black; a soot; carbonizing fibers, flakes or powders; carbon nanotubes, fullerenes, graphene oxide or graphite nanoplatelets.

5. The polymeric foam insulation panel of any one of claims 1-4, wherein the first facing layer comprises at least one oxygen barrier layer comprising an ethylene-vinyl alcohol copolymer and at least one moisture barrier layer on each side of the oxygen barrier layer.

6. The polymeric foam insulation panel of any one of claims 1-5, wherein the first facing layer comprises an inner moisture barrier comprising an ethylene vinyl acetate polymer; an oxygen barrier layer comprising an ethylene-vinyl alcohol copolymer; an outer moisture barrier comprising polyethylene, at least one reflective filler and/or at least one ultraviolet light absorber; and an adhesive layer disposed between each of the oxygen barrier layer and the moisture barrier layer.

7. The polymeric foam insulation panel of claim 6, wherein the outer moisture barrier comprises titanium dioxide, calcium carbonate, or both titanium dioxide and calcium carbonate.

8. The polymeric foam insulation panel of any one of claims 1-7, wherein the second facing comprises at least one oxygen barrier layer comprising an ethylene-vinyl alcohol copolymer and at least one moisture barrier layer on each side of the oxygen barrier layer.

9. The polymeric foam insulation panel of any one of claims 1-8, wherein the second facing layer comprises an inner moisture barrier comprising an ethylene vinyl acetate polymer; an oxygen barrier layer comprising an ethylene-vinyl alcohol copolymer; an outer moisture barrier comprising polyethylene, at least one reflective filler and/or at least one ultraviolet light absorber; and an adhesive layer disposed between each of the oxygen barrier layer and the moisture barrier layer.

10. The polymeric foam insulation panel of any one of claims 1-9, wherein the first facing layer and the second facing layer are the same.

11. The polymeric foam insulation panel of any one of claims 1-10, notched engaged along one or more edges.

12. An inverted roofing membrane assembly comprising:

A. floor support plate;

B. a waterproof membrane mounted directly or indirectly on top of the floor support plate;

C. at least one layer of the polymer foam insulation panel of any one of claims 1 to 11 directly or indirectly on top of layer B; and

D. a ballast layer directly or indirectly on top of layer C.

13. The inverted roof membrane assembly of claim 12, wherein the ballast comprises gravel, stone, soil, one or more paving materials, green roof structures or components thereof, or blue roof structures or components thereof.