ASPHALT-BASED ROOFING MEMBRANE COMPOSITE

FIELD OF THE INVENTION

[0001] Embodiments of the present invention are directed toward asphalt-based roofing membrane composites including an adhesive layer.

BACKGROUND OF THE INVENTION

[0002] Within the construction industry, membranes are often employed to cover flat or low-sloped roofs. These membranes may include rubber membranes, plastic membranes, and asphalt-based membranes. Asphalt-based membranes provide an economic alternative to the more expensive rubber and plastic membrane systems. The asphalt-based membranes are typically modified with polymers such as styrene- butadiene-styrene block copolymers (SBS) or atactic polypropylene (APP). In fact, many commercial suppliers of asphalt-based membranes offer SBS-modified asphalt membranes and APP-modified asphalt membranes.

[0003] Asphalt-based membranes are typically installed by applying multiple membrane layers. Generally, the asphalt-based membranes include cap sheets and base sheets, where the cap sheets form the top layer, which is exposed to the environment, and the base sheets form the underlying layers.

[0004] Several modes of attachment are used to secure both the base sheets and cap sheets to the roof structure. Generally, the membranes can be secured by ballasting, mechanical attachment means, or by adhesive means. Adhesives can be bifurcated into hot and cold adhesive techniques. In the former technique, hot asphalt is often used in combination with the membranes to create the roofing system. In the latter technique, often referred to as cold bonding, the membranes are secured to the roof by using a liquid adhesive or by using the adhesive properties of the membrane itself (i.e. self- adhering membranes). For example, since the asphalt may inherently have adhesive properties, especially where the asphalt composition is modified with polymer and/or tackifiers, the asphalt itself can be used to secure the asphalt-based membranes directly to the underlying surface. The ability to directly secure the asphalt-based membrane to the underlying surface is advantageous because mechanical fasteners and/or liquid adhesives are not required, which not only reduces costs associated with accessories, but also a labor savings can be realized.

[0005] One drawback, however, to a self-adhering asphalt-based membrane is that the asphalt itself must offer the adhesion. As a result, care must be taken not employ additives or modifiers within the asphalt composition that may interfere with the inherent adhesive properties of the asphalt. For example, it may be desirable to load appreciable amounts of flame retardant or other filler into the asphalt material to impart, among other properties, flame resistance. While relatively high loadings of these materials have proven useful in allowing, for example, asphalt-based membranes to be used to construct roof systems that pass the most stringent roofing standards for fire performance (e.g., class A roof systems under UL 790 standards), the use of appreciable amounts of filler compromises the ability to bond the membrane to the roof surface. Where appreciable amounts of flame retardant are added to the asphalt composition of a self-adhering asphalt-based membrane, the roof systems may not be able to achieve applicable roofing standards for wind uplift (e.g., wind uplift according to UL 1897 and UL 590).

[0006] Attempts have been made to alleviate issues with self-adhering asphalt-based membranes. This technology involves employing two distinct asphalt-based compositions to prepare opposing planar surfaces of the membrane. For example, it is known to prepare an asphalt-based membrane by employing conventional polymer- modified asphalt compositions to coat a reinforcing fabric. Once coated, and while in the molten state, the polymer-modified asphalt is removed from one planar surface of the fabric reinforcement. After removal of this polymer-modified asphalt composition, a second asphalt composition, which has greater tack than the polymer-modified asphalt composition, is applied to the composite in a location where the previous polymer- modified asphalt was removed. The production of these membrane composites is obviously complicated from the manufacturing standpoint and requires the formulation of two separate asphalt-based compositions. SUMMARY OF THE INVENTION

[0007] Embodiments of the invention provide an asphalt-based composite comprising an asphaltic body having opposed planar surfaces; and a pressure-sensitive adhesive layer disposed on at least one of the planar surfaces of the asphaltic body.

[0008] Other embodiments of the invention provide a roofing system comprising a roof deck; an optional layer of construction board; at least one layer of asphaltic-based base composite membranes; and at least one layer of asphaltic-based cap sheet membranes, where at least one of the layer of base sheet membranes or cap sheet membranes is secured to the roof system through a cured pressure-sensitive adhesive.

[0009] Still other embodiments of the invention provide A method for producing an asphaltic-based composite membrane, the process comprising saturating a fabric with asphaltic material to form a saturated fabric; optionally applying a surface coating to one planar surface of the saturated fabric; applying a layer of pressure-sensitive adhesive to a planar surface of the saturated fabric to form an uncured layer of pressure-sensitive adhesive; curing the layer of pressure-sensitive adhesive to form a layer of cross-linked pressure-sensitive adhesive; applying a release member to the layer of pressure-sensitive adhesive to form the composite membrane; and optionally winding the composite membrane to form a roll of the composite membrane.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Fig. 1 is a cross-sectional perspective view of an asphalt-based roofing membrane composite including a single layer of pressure-sensitive adhesive according to embodiments of the invention.

[0011] Fig. 2 is a cross-sectional perspective view of an asphalt-based roofing membrane composite including two opposing layers of pressure-sensitive adhesive according to embodiments of the invention.

[0012] Fig. 3 is a cross-sectional perspective view of an asphalt-based roofing membrane composite including a single layer of pressure-sensitive adhesive and a barrier layer according to embodiments of the invention. [0013] Fig. 4 is a cross-sectional perspective view of an asphalt-based roofing membrane composite including a granular layer and a lap region according to embodiments of the present invention.

[0014] Fig. 5 is a cross-sectional perspective view of an asphalt-based roofing membrane composite including a granular layer according to embodiments of the present invention.

[0015] Fig. 6 is a schematic view of a process for producing membrane composite according to embodiments of the invention wherein pressure-sensitive adhesive is applied as a hot-melt directly to an asphalt membrane.

[0016] Fig. 7 is a schematic view of a process for producing membrane composite according to embodiments of the invention wherein hot-melt pressure-sensitive adhesive is applied to a transfer film and then applied to an asphalt membrane.

[0017] Fig. 8 is a schematic drawing of a roof system according to embodiments of the present invention.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

[0018] Embodiments of the invention are based, at least in part, on the discovery of an asphalt-based roofing membrane composite having a layer of pressure-sensitive adhesive applied to a surface of the membrane. As a result, the membrane composites can be installed by using peel-and-stick techniques. Moreover, since the adhesive layer is distinct from the asphalt body itself, the asphalt body can include sufficient filler and/or flame retardant material to allow the membranes to be used in the construction of UL 790 Class A roofing systems. In one or more embodiments, the pressure-sensitive adhesive composition applied to the asphalt-based membranes in accordance with this invention includes a melt-extrudable composition that is subsequently cured. As a result, the adhesive can be efficiently applied to the membrane, and the subsequent crosslinking provides strength necessary to provide adequate peel adhesion to the underlying surface. As a result, the membranes can be installed, using peel-and-stick methods, to provide roof systems that meet some of the most stringent industry standards for wind uplift (e.g. UL 1897 and UL 590). COMPOSITE STRUCTURE

[0019] Embodiments of the invention can be described with reference to Fig. 1, which shows membrane composite 11 including asphaltic body 13, pressure-sensitive adhesive layer 17, and release member 21. Pressure-sensitive adhesive layer 17 is fixedly disposed on a planar surface 18 of asphaltic body 13 to form an interface 19. In one or more embodiments, adhesive layer 17 is coextensive with the width and length of asphaltic body 13; i.e. it is coextensive with planar surface 18. In other embodiments, adhesive layer 17 is disposed on only a portion of planar surface 18.

[0020] Release member 21 is removably disposed on a planar surface 20 of pressure- sensitive adhesive layer 17 to thereby form an interface 23. In one or more embodiments, release member 21 is coextensive with the width and length of asphaltic body 13; e.g. it is coextensive with adhesive layer 17 where adhesive layer 17 is coextensive with asphaltic body 13. In one or more embodiments, multiple release members are disposed on planar surface 20, where each member 21 covers a portion of adhesive layer 17. In one or more embodiments, release member 21 includes perforations or is otherwise divided to provide a mechanisms by which release member 21 can be removed from adhesive layer 17 is segments or portions.

[0021] Asphaltic body 13 includes opposed planar surfaces 16 and 18, which may be referred to as upper surface 16 and lower surface 18. At installation and during use, the upper surface is positioned toward the environment while the lower surface is positioned toward the roof structure on to which the membrane is installed.

[0022] In one or more embodiments, composite 11 includes opposing layers of adhesive, which provides ability to not only secure composite 11 to a substrate surface, but subsequent layers, such as subsequent layers of asphaltic membrane, can be applied to and secured to the upper, opposing surface of the asphaltic membrane. For example, and with reference to Fig. 2, composite 11 may include those elements described above with respect to Fig. 1, and also includes pressure-sensitive adhesive layer 27 and release member 31. Pressure-sensitive adhesive layer 27 is fixedly disposed on upper planar surface 16 of asphaltic body 13 to form an interface 29. As with adhesive layer 17, adhesive layer 27 may be coextensive with the width and length of asphaltic body 13; i.e. it is coextensive with planar surface 16. In other embodiments, adhesive layer 27 is disposed on only a portion of planar surface 16. Release member 31 may be removably disposed on a planar surface 30 of pressure-sensitive adhesive layer 27 to thereby form an interface 33. As with the previous embodiments, release member 31 may be coextensive with the width and length of asphaltic body 13; e.g. it is coextensive with adhesive layer 27 where adhesive layer 27 is coextensive with asphaltic body 13. In one or more embodiments, multiple release members are disposed on planar surface 30, where each member 31 covers a portion of adhesive layer 27. In one or more embodiments, release member 31 includes perforations or is otherwise divided to provide a mechanism by which release member 31 can be removed from adhesive layer 27 is segments or portions.

[0023] Other embodiments of the present invention are shown in Fig. 3. As with the previous embodiments, composite 11 includes asphaltic body 13 (including layers 15, 15'), pressure-sensitive adhesive layer 17, and release member 21. Additionally, composite 11 includes barrier layer 25 disposed between pressure-sensitive adhesive layer 17 and asphaltic body 13 (adjacent layer 15'). As will be described in greater detail below, barrier 25 protects pressure-sensitive adhesive layer 17 from constituents of asphaltic body 13 that can migrate to pressure-sensitive adhesive layer 17. With reference to Fig. 2, the skilled person can readily envision those embodiments where a similar barrier layer exists between asphaltic component 13 (adjacent layer 15) and pressure-sensitive adhesive layer 27.

[0024] In yet other embodiments, the composite of the present invention may include an additional layer disposed on the asphaltic body opposite the pressure-sensitive adhesive. For example, as shown in Fig. 4, composite 11 may include a layer of granular material 30 disposed on asphaltic body 13 (adjacent layer 15); i.e. on planar surface 16 of asphaltic component 13. In one or more embodiments, granular material 30 is not disposed on planar surface 16 at lap area 31. In lieu of granular material 30, a protective tape or coating 33 may be disposed on surface 16, either directly or indirectly, to prevent granular material from adhering to surface 16 or otherwise being present within lap area 31. In one or more embodiments, tape or coating 33 is fixedly attached, directly or indirectly, to surface 16 of asphaltic component 13. In other embodiments, tape 33 is removably attached, either directly or indirectly, to surface 16 of asphaltic component 13. In other embodiments, as shown in Fig. 5, granular material 30 extends the entire width of composite 11.

[0025] Whether granular material 30 extends the entire width of composite 11, as shown in Fig. 5, or whether it only partially covers the width (thereby leaving lap area 31) as shown in Fig. 4, lap area 31 may include a barrier layer 35 as shown in Figs. 4 and 5. As with barrier 25 shown in Fig. 3, barrier 35 serves to protect a mated pressure- sensitive adhesive layer (i.e. pressure-sensitive adhesive from an adjacent composite applied to and adhered to lap region 31) from constituents within asphaltic body 13 that can migrate to the mated pressure-sensitive adhesive layer.

[0026] The skilled person will also appreciate that in lieu of granular material, the composites of the present invention may carry an additional layer disposed on planar surface 16 of asphaltic body 13. This layer may include a polymeric layer or fabric that is fixedly attached to asphaltic body 13. For example, a polyolefm layer may be fixedly secured to surface 16.

ASPHALTIC BODY

[0027] Embodiments of the invention are not necessarily limited by the composition and construction of the asphaltic body 13, which may also be referred to as asphaltic sheet 13, asphaltic substrate 13, and asphaltic membrane 13. Examples of asphaltic bodies are disclosed in U.S. Patent Nos. 4,835,199, 4,992,315, 6,486,236, 6,492,439, 6,924,015, 7,070,843, 7,146,771, and 7,442,270, which are incorporated herein by reference. As shown in Fig. 1, asphaltic body 13 may include a fabric 14, which may be referred to as a reinforcing fabric or scrim 14, that has been coated or saturated with an asphaltic composition, which composition will be described in greater detail below. In one or more embodiments, as shown in Fig. 1, the asphaltic component forms upper layer 15 and lower layer 17 on either side of fabric 14. As the skilled person will appreciate, asphaltic material also saturates and fills interstices within fabric 14.

[0028] In one or more embodiments, the thickness of asphaltic body 13 may be at least 1000 μπι, in other embodiments at least 1250 μπι, and in other embodiments at least 1500 μπι. In these or other embodiments, the thickness of asphaltic body 13 may be at most 6.5 mm, in other embodiments at most 5.5 mm, and in other embodiments at most 4.5 mm. In one or more embodiments, the thickness of asphaltic body 13 may be from about 1000 μπι to about 6.5 mm, in other embodiments from about 1250 μπι to about 5.5 mm, and in other embodiments from about 1500 μπι to about 4.5 mm.

ASPHALT CONSTITUENTS

[0029] As noted above, the asphaltic sheet of one or more embodiments of the present invention includes an asphaltic component. The asphaltic component includes an asphalt binder. The asphaltic component may also include, dispersed within the binder, polymeric modifiers, fillers, tackifiers, flame retardants, and other constituents conventionally used in asphaltic-based building materials.

ASPHALT BINDER

[0030] The term "asphalt binder" is used as understood by those skilled in the art and is consistent with the meaning provided by AASHTO M320. As used within this specification, the terms "asphalt" and "asphalt binder" may be used synonymously. The asphalt binder material may be derived from any asphalt source, such as natural asphalt, rock asphalt, produced from tar sands, or petroleum asphalt obtained in the process of refining petroleum. In other embodiments, asphalt binders may include a blend of various asphalts not meeting any specific grade definition. This includes air-blown asphalt, vacuum- distilled asphalt, steam-distilled asphalt, cutback asphalt or roofing asphalt. Alternatively, gilsonite, natural or synthetic, used alone or mixed with petroleum asphalt, may be selected. Synthetic asphalt mixtures suitable for use in the present invention are described, for example, in U.S. Pat. No. 4,437,896. In one or more embodiments, asphalt includes petroleum derived asphalt and asphaltic residual. These compositions may include asphaltenes, resins, cyclics, and saturates. The percentage of these constituents in the overall asphalt binder composition may vary based on the source of the asphalt.

[0031] Asphaltenes include black amorphous solids containing, in addition to carbon and hydrogen, some nitrogen, sulfur, and oxygen. Trace elements such as nickel and vanadium may also be present. Asphaltenes are generally considered as highly polar aromatic materials of a number average molecular weight of about 2000 to about 5000 g/mol, and may constitute about 5 to about 25% of the weight of asphalt.

[0032] Resins (polar aromatics) include dark-colored, solid and semi-solid, very adhesive fractions of relatively high molecular weight present in the maltenes. They may include the dispersing agents of peptizers for the asphaltenes, and the proportion of resins to asphaltenes governs, to a degree, the sol-or gel-type character of asphalts. Resins separated from bitumens may have a number average molecular weight of about 0.8 to about 2 kg/mol but there is a wide molecular distribution. This component may constitute about 15 to about 25% of the weight of asphalts.

[0033] Cyclics (naphthene aromatics) include the compounds of lowest molecular weight in bitumens and represent the major portion of the dispersion medium for the peptized asphaltenes. They may constitute about 45 to about 60% by weight of the total asphalt binder, and may be dark viscous liquids. They may include compounds with aromatic and naphthenic aromatic nuclei with side chain constituents and may have molecular weights of 0.5 to about 9 kg/mol.

[0034] Saturates include predominantly the straight-and branched-chain aliphatic hydrocarbons present in bitumens, together with alkyl naphthenes and some alkyl aromatics. The average molecular weight range may be approximately similar to that of the cyclics, and the components may include the waxy and non-waxy saturates. This fraction may from about 5 to about 20% of the weight of asphalts.

[0035] In these or other embodiments, asphalt binders may include bitumens that occur in nature or may be obtained in petroleum processing. Asphalts may contain very high molecular weight hydrocarbons called asphaltenes, which may be soluble in carbon disulfide, pyridine, aromatic hydrocarbons, chlorinated hydrocarbons, and THF. Asphalts or bituminous materials may be solids, semi-solids or liquids.

[0036] In one or more embodiments, the asphalt binder includes AC-5, AC-10 and AC-15. These asphalts typically contain about 40 to about 52 parts by weight of aromatic hydrocarbons, about 20 to about 44 parts by weight of a polar organic compound, about 10 to about 15 parts by weight of asphalt ene, about 6 to about 8 parts by weight of saturates, and about 4 to about 5 parts by weight of sulfur. Nevertheless, practice of the present invention is not limited by selection of any particular asphalt.

[0037] In one or more embodiments, the molecular weight of the aromatic hydrocarbons present in asphalt may range between about 300 and 2000, while the polar organic compounds, which generally include hydroxylated, carboxylated and heterocyclic compounds, may have a weight average molecular weight of about 500 to 50,000. Asphaltenes, which are generally known as heavy hydrocarbons, are typically of a high molecular weight and are heptane insoluble. Saturates generally include paraffmic and cycloaliphatic hydrocarbons having about 300 to 2000 molecular weight.

[0038] In one or more embodiments, bitumens may be used. Bitumens are naturally occurring solidified hydrocarbons, typically collected as a residue of petroleum distillation. Gilsonite is believed to be the purest naturally formed bitumen, typically having a molecular weight of about 3,000 with about 3 parts by weight complexed nitrogen.

TACKIFIERS

[0039] In one or more embodiments, the asphaltic component may include tackifier resins. These resins include, but are not limited to, petroleum resins, synthetic polyterpenes, resin esters and natural terpenes, and combinations thereof. In certain embodiments, the resin modifiers soften or become liquid at temperatures of about 40° C to about 150° C. In certain embodiments, the resin modifiers have number average molecular weights, as measured by vapor phase osmometry, below that of the polymeric material included in the polymeric film. In certain embodiments, the number average molecular weights of the resin modifiers are less than about 5,000. In other embodiments, the number average molecular weights of the resin modifiers are less than about 1,000. In additional embodiments, the number average molecular weights of the resin modifiers are from about 500 to about 1000.

[0040] In certain embodiments, the resin modifiers have ring and ball softening point of about 20° C to about 160° C. In additional embodiments, resin modifiers have ring and ball softening points of about 40° C to about 160° C. In still other embodiments, resin modifiers have ring and ball softening points of about 50° C to about 160° C. [0041] Various types of natural and synthetic resins, alone or in admixture with each other, may be used be selected as the resin modifier. Suitable resins include, but are not limited to, natural rosins and rosin esters, hydrogenated rosins and hydrogenated rosin esters, coumarone-indene resins, petroleum resins, polyterpene resins, and terpene- phenolic resins. Specific examples of suitable petroleum resins include, but are not limited to, aliphatic hydrocarbon resins, hydrogenated aliphatic hydrocarbon resins, mixed aliphatic and aromatic hydrocarbon resins, hydrogenated mixed aliphatic and aromatic hydrocarbon resins, cycloaliphatic hydrocarbon resins, hydrogenated cycloaliphatic resins, mixed cycloaliphatic and aromatic hydrocarbon resins, hydrogenated mixed cycloaliphatic and aromatic hydrocarbon resins, aromatic hydrocarbon resins, substituted aromatic hydrocarbons, and hydrogenated aromatic hydrocarbon resins. As used herein, "hydrogenated" includes fully, substantially and at least partially hydrogenated resins. Suitable aromatic resins include aromatic modified aliphatic resins, aromatic modified cycloaliphatic resin, and hydrogenated aromatic hydrocarbon resins. Any of the above resins may be grafted with an unsaturated ester or anhydride to provide enhanced properties to the resin. For additional description of resin modifiers, reference can be made to technical literature, e.g., Hydrocarbon Resins, Kirk-Othmer, Encyclopedia of Chemical Technology, 4th Ed. v.13, pp. 717-743 (J. Wiley & Sons, 1995).

[0042] In one or more embodiments, the tackifier resins include phenol-based resins. Included among the phenol-based resins are phenolic resins. These resins may include reactive phenol resins (also referred to as functionalized phenol resins), as well as unreactive resins. In one or more embodiments, the phenolic resin is a resole resin, which can be made by the condensation of alkyl, substituted phenols, or unsubstituted phenols with aldehydes such as formaldehyde in an alkaline medium or by condensation of bi-functional phenoldialcohols. In one or more embodiments, this condensation reaction occurs in the excess or molar equivalent of formaldehyde. In other embodiments, the phenolic resin may be formed by an acid-catalyzed reaction.

In one or more embodiments, the tackifier resin is a polybutene polymer or oligomer. In particular embodiments, polybutene oils are employed. Useful polybutene oils include high- viscosity oils that may be characterized by a viscosity at 100 °C of at least 80 est, in other embodiments at least 100 est, or in other embodiments at least 120 est up to, for example, about 700 or 800 est. In these or other embodiments, the high viscosity polybutene oils may be characterized by a molecular weight of at least 1000 g/mole, in other embodiments at least 1200 g/mole, or in other embodiments at least 1300 g/mole up to, for example, 1400 or 1500 g/mole. An exemplary high-viscosity polybutene oil is available under the tradename Indapol H300 (Ineos) or PB32 (Soltex).

POLYMERIC MODIFIERS

[0043] In one or more embodiments, the polymeric modifier, which may simply be referred to as polymer, includes thermoplastic polymers, thermosetting elastomers, thermoplastic elastomers, and/or mixtures thereof. Each of these polymers have been used, either alone or in combination with each other to modify asphalt binders, and practice of the present invention is not necessarily limited by the selection of any particular polymeric modifier.

[0044] In one or more embodiments, the polymers may be characterized by a glass transition temperature (Tg), as measured by DSC analysis, of less than 150°C, in other embodiment less than 125°C, in other embodiment less than 100°C, in other embodiments less than 20°C, in other embodiments less than 0°C, in other embodiments less than -20°C, in other embodiments less than -35°C, and in other embodiments from about -90°C to about -20°C. In these or other embodiments, the polymers may be characterized by a glass transition temperature (Tg), as measured by DSC analysis, of more than -20°C, in other embodiments more than 0°C, in other embodiments more than 20°C, in other embodiments more than 50°C, and in other embodiments more than 100°C.

[0045] In one or more embodiments, the polymeric modifier may be characterized by a melt index (ASTM D-1238; 2.16 kg load @ 190°C) of less than 1,000 dg/min, in other embodiments less than 500 dg/min, in other embodiments less than 50 dg/min, in other embodiments less than 20 dg/min, in other embodiments less than 10 dg/min, and in other embodiments less than 1 dg/min. In these or other embodiments, the unsaturated polymers may have a melt index of between 3 and 15 dg/min, and other embodiments between 4 and 12 dg/min.

[0046] In one or more embodiments, the polymeric modifier may be characterized by a number average molecular weight (M _n ) of from about 10 to about 1,000 kg/mol, in other embodiments from about 40 to about 500 kg/mol, and in other embodiments from about 80 to about 200 kg/mol. In these or other embodiments, the polymeric modifier may also be characterized by a weight average molecular weight (M _w ) of from about 10 to about 4,000 kg/mol, in other embodiments from about 40 to about 2,000 kg/mol, and in other embodiments from about 80 to about 800 kg/mol. In one or more embodiments, the polymeric modifier may be characterized by a molecular weight distribution of from about 1.1 to about 5, in other embodiments from about 1.5 to about 4.5, and in other embodiments from about 1.8 to about 4.0. Molecular weight can be determined by gel permeation chromatography (GPC) calibrated with polystyrene standards and adjusted for the Mark-Houwink constants for the polymer in question.

[0047] The polymeric modifier may be linear, branched, or coupled polymers. Types of polymers may include both natural and synthetic polymers. Useful synthetic polymers may include polydienes or polydiene copolymers with non-diene comonomer {e.g., styrene). The copolymers may include block and random copolymers. The coupled polymers may include linearly coupled polymers (e.g. di-coupled polymers) or radially coupled polymers (e.g. tri-coupled or, tetra-coupled penta-coupled, hexa-coupled etc.). Exemplary polydienes include polybutadiene and polyisoprene. Exemplary copolymers may include random styrene-butadiene rubber, styrene-butadiene block copolymer, styrene-butadiene-styrene block copolymer, random styrene-isoprene, styrene-isoprene block copolymer, styrene-isoprene-butadiene block copolymer, random styrene-isoprene- butadiene, styrene-isoprene-styrene block copolymer, and chloroprene rubber. In one or more embodiments, the polymeric modifier includes linear or radial block copolymers wherein the block copolymers include terminal styrene blocks. In these or other embodiments, the styrene content of these block copolymers may be from 10% to 50% by weight, in other embodiments from 15% to 45% by weight, and in other embodiments from 20% to 40% by weight. [0048] In one or more embodiments, the polymeric modifier is an SBS block copolymer (i.e. poly(styrene-b-butadiene-b-styrene). In one or more embodiments, these block copolymers may be characterized by a weight average molecular weight of from about 90,000 to about 750,000, or in other embodiments from about 150,000 to about 250,000. In these or other embodiments, these polymers may be characterized by a polydispersity of up to about 1.1 or in other embodiments up to about 1.05. In particular embodiments, the SBS block copolymers have from about 27 to about 43 parts by weight of styrene.

[0049] An example of an SBS block copolymer useful for practice of the present invention is that sold under the tradename Kraton D (Kraton Polymer Group), including, for example, D1118, D1101, and D1184. Included among these polymers are SBS block linear and radial block copolymers. In particular embodiments, two block copolymers, linear and radial, can be mixed to achieve the desired results. In certain embodiments, the weight ratio of linear to radial SBS copolymers may be from about 0 to about 7 parts by weight of radial and from about 7 to about 15 parts by weight of linear SBS block copolymer.

[0050] In one or more embodiments, useful thermoplastic polymers that may be used as the polymeric modifier include polyolefms. For example, several derivatives of polypropylene are useful including those prepared by first dimerizing propylene to give 4-methyl-l-pentene and subsequently polymerizing this dimer to give poly- 4-methyl-l- pentene. These polypropylenes may have a weight average molecular weight of from about 50,000 to about 250,000, or in other embodiments from about 150,000 to about 170,000. In one or more embodiments, the polydispersity may be from about 2.5 to about 3.5. The polypropylene may be further characterized by a melt temperature of from about 160° C to about 175 ° C, and may have a cold crystallization temperature above 120° C.

[0051] In one or more embodiments, the polymeric modifier is isotactic polypropylene (IPP). In one or more embodiments, the IPP has at least 45 percent by weight crystallinity, or in other embodiments from about 46 to about 50 percent by weight crystallinity. Blends of atactic polypropylene and isotactic polypropylene may be used. In yet other embodiments, atactic polyalpha olefins (APAOs) may be used.

FILLERS

[0052] In one or more embodiments, fillers that may be included within the asphalt composition include inorganic materials. In other embodiments, these materials are generally inert with respect to the composition therefore simply act as. In one or more embodiments, mineral fillers include clays, silicates, titanium dioxide, talc (magnesium silicate), mica (mixtures of sodium and potassium aluminum silicate), alumina trihydrate, antimony trioxide, calcium carbonate, titanium dioxide, silica, magnesium hydroxide, calcium borate ore, and mixtures thereof. In one or more embodiments, the fillers are not surface modified or surface functionalized.

[0053] Suitable clays may include airfloated clays, water-washed clays, calcined clays, surface-treated clays, chemically-modified clays, and mixtures thereof.

[0054] Suitable silicates may include synthetic amorphous calcium silicates, precipitated, amorphous sodium aluminosilicates, and mixtures thereof.

[0055] Suitable silica (silicon dioxide) may include wet-processed, hydrated silicas, crystalline silicas, and amorphous silicas (noncrystalline).

[0056] In one or more embodiments, the mineral fillers are characterized by an average particle size of at least 1 μπι, in other embodiments at least 2 μπι, in other embodiments at least 3 μπι, in other embodiments at least 4 μπι, and in other embodiments at least 5 μπι. In these or other embodiments, the mineral fillers are characterized by an average particle size of less than 15 μπι, in other embodiments less than 12 μπι, in other embodiments less than 10 μπι, and in other embodiments less than 8μπι. In these or other embodiments, the mineral filler has an average particle size of between 1 and 15 μπι, in other embodiments between 3 and 12 μπι, and in other embodiments between 6 and 10 μπι.

FLAME RETARDANTS

[0057] In one or more embodiments, useful flame retardants include and compound that will increase the burn resistivity, particularly flame spread such as tested by UL 94 and/or UL 790, of the composites of the present invention when employed within a roofing system. Useful flame retardants include those that operate by forming a char- layer across the surface of a specimen when exposed to a flame. Other flame retardants include those that operate by releasing water upon thermal decomposition of the flame retardant compound. Useful flame retardants may also be categorized as halogenated flame retardants or non-halogenated flame retardants.

[0058] Exemplary non-halogenated flame retardants include magnesium hydroxide, aluminum trihydrate, zinc borate, ammonium polyphosphate, melamine polyphosphate, and antimony oxide (Sb203). Magnesium hydroxide (Mg(OH)2) is commercially available under the tradename Vertex™ 60, ammonium polyphosphate is commercially available under the tradename Exolite™ AP 760 (Clarian), which is sold together as a polyol masterbatch, melamine polyphosphate is available under the tradename Budit™ 3141 (Budenheim), and antimony oxide (Sb203) is commercially available under the tradename Fireshield™. Those flame retardants from the foregoing list that are believed to operate by forming a char layer include ammonium polyphosphate and melamine polyphosphate.

[0059] In one or more embodiments, treated or functionalized magnesium hydroxide may be employed. For example, magnesium oxide treated with or reacted with a carboxylic acid or anhydride may be employed. In one embodiment, the magnesium hydroxide may be treated or reacted with stearic acid. In other embodiments, the magnesium hydroxide may be treated with or reacted with certain silicon-containing compounds. The silicon-containing compounds may include silanes, polysiloxanes including silane reactive groups. In other embodiments, the magnesium hydroxide may be treated with maleic anhydride. Treated magnesium hydroxide is commercially available. For example, Zerogen™ 50.

[0060] Examples of halogenated flame retardants may include halogenated organic species or hydrocarbons such as hexabromocyclododecane or N,N'-ethylene-bis- (tetrabromophthalimide) . Hexabromocyclododecane is commercially available under the tradename CD-75P™ (ChemTura). N,N'-ethylene-bis-(tetrabromophthalimide) is commercially available under the tradename Saytex™ BT-93 (Albemarle). [0061] In one or more embodiments, the use of char- forming flame retardants (e.g. ammonium polyphosphate and melamine polyphosphate) has unexpectedly shown advantageous results when used in conjunction with nanoclay within the cap layer of the laminates of the present invention. It is believed that there may be a synergistic effect when these compounds are present in the cap layer. As a result, the cap layer of the laminates of the certain embodiments of the present invention are devoid of or substantially devoid of halogenated flame retardants and/or flame retardants that release water upon thermal decomposition. Substantially devoid referring to that amount or less that does not have an appreciable impact on the laminates, the cap layer, and/or the burn resistivity of the laminates.

[0062] In one or more embodiments, the membranes of the invention may include stabilizers. Stabilizers may include one or more of a UV stabilizer, an antioxidant, and an antiozonant. UV stabilizers include Tinuvin™ 622. Antioxidants include Irganox™ 1010.

[0063] In one or more embodiments, one or more layers of the membranes of the present invention may include expandable graphite, which may also be referred to as expandable flake graphite, intumescent flake graphite, or expandable flake. Generally, expandable graphite includes intercalated graphite in which an intercallant material is included between the graphite layers of graphite crystal or particle. Examples of intercallant materials include halogens, alkali metals, sulfates, nitrates, various organic acids, aluminum chlorides, ferric chlorides, other metal halides, arsenic sulfides, and thallium sulfides. In certain embodiments of the present invention, the expandable graphite includes non- halogenated intercallant materials. In certain embodiments, the expandable graphite includes sulfate intercallants, also referred to as graphite bisulfate. As is known in the art, bisulfate intercalation is achieved by treating highly crystalline natural flake graphite with a mixture of sulfuric acid and other oxidizing agents which act to catalyze the sulfate intercalation. Expandable graphite useful in the applications of the present invention are generally known as described in International Publ. No. WO/2014/078760, which is incorporated herein by reference. [0064] In one or more embodiments, the asphaltic body, and therefore the asphalt composition employed to make the asphaltic body, includes threshold amounts of non- asphaltic or non-polymeric materials such as mineral fillers and/or flame retardants. In one more embodiments, the asphaltic body of the composites of the present invention include at least 15 wt %, in other embodiments at least 20 wt %, in other embodiments at least 25 wt %, and in other embodiments at least 35 wt % by weight mineral filler and/or flame retardant, based upon the entire weight of the asphaltic body (excluding any fabric). In these or other embodiments, asphaltic body of the composites of the present invention include from about 15 to about 55 wt %, in other embodiments from about 20 to about 50 wt %, and in other embodiments from about 25 to about 45 wt % mineral filler and/or flame retardant, based upon the entire weight of the asphaltic body (excluding any fabric) .

REINFORCING FABRIC

[0065] Reinforcing fabric 14, which may be referred to as reinforcing sheet 14 or simply fabric 14, may be woven or non-woven. In one or more embodiments, the fabric may include a polyester scrim including those meeting the specifications of ASTM D- 6164. In other embodiments, the fabric may include a polyester-fiberglass composite including those meeting the specifications of ASTM D-6162. In other embodiments, the fabric may include a fiberglass reinforced mesh sheet including those meeting the specifications of ASTM D-6163.

RELEASE MEMBER

[0066] In one or more embodiments, release member 21 may include a polymeric film or extrudate, or in other embodiments it may include a cellulosic substrate. In one or more embodiments, the polymeric film and/or cellulosic substrate can carry a coating or layer that allows the polymeric film and/or cellulosic substrate to be readily removed from the adhesive layer after attachment. This polymeric film or extrudate may include a single polymeric layer or may include two or more polymeric layers laminated or coextruded to one another.

[0067] Suitable materials for forming a release member that is a polymeric film or extrudate include polypropylene, polyester, high-density polyethylene, medium-density polyethylene, low-density polyethylene, polystyrene or high-impact polystyrene. The coating or layer applied to the film and/or cellulosic substrate may include a silicon- containing or fluorine-containing coating. For example, a silicone oil or polysiloxane may be applied as a coating. In other embodiments, hydrocarbon waxes may be applied as a coating. As the skilled person will appreciate, the coating, which may be referred to as a release coating, can be applied to both planar surfaces of the film and/or cellulosic substrate. In other embodiments, the release coating need only be applied to the planar surface of the film and/or cellulosic substrate that is ultimately removably mated with the adhesive layer.

[0068] In one or more embodiments, the release member is characterized by a thickness of from about 15 to about 80 μπι, in other embodiments from about 18 to about 75 μπι, and in other embodiments from about 20 to about 50 μπι.

BARRIER LAYER

[0069] In one or more embodiments, barrier layer 25, as well as barrier layer 35 in lap region 31, may include a polymeric layer that is chemically resistant to asphaltic constituents. The layer can include thermoplastic or thermoset layers. In one or more embodiments, this thermoplastic layer may include a layer of polyolefm such as polyethylene or polypropylene. The barrier may derive from a polymeric sheet or film applied to the membrane, or it may derive from a coating composition applied to the surface of the membrane.

[0070] In one or more embodiments, the barrier layer may have a thickness of greater than 10 μπι, in other embodiments greater than 25 μπι, and in other embodiments greater than 50 μπι. In these or other embodiments, the barrier layer may have a thickness of less than 200 μπι, in other embodiments of less than 150 μπι, and in other embodiments of less than 100 μπι. In one or more embodiments, the thickness of barrier layer may be from about 10 to about 200, in other embodiments from about 25 to about 150, and in other embodiments from about 50 to about 100 μπι.

[0071] In one or more embodiments, barrier layer 25 (as well as barrier layer 35) is fixedly adhered to the planar surface on which it is disposed. For example, barrier layer 25 is fixedly secured to planar surface 18 of asphaltic body 13. As a skilled person will appreciate, inasmuch as pressure-sensitive adhesive layer 17 is employed to secure composite 11 to a roof substrate, barrier layer 25 should be secured to asphaltic body 13 in a manner consistent with the overall strength desired by the roof system. Accordingly, in one or more embodiments, the barrier layer is secured to the asphaltic body in a manner such that the overall composite, when secured to a roof substrate, will resist wind uplift forces of at least 40, in other embodiments at least 60, in other embodiments at least 80, in other embodiments at least 90, and in other embodiments at least 100 pounds per square foot.

GRANULAR MATERIAL

[0072] Embodiments of the invention are not limited by the type of granular material employed. For example, both natural and synthetic materials may be employed. These materials are known in the art as disclosed in Publication Number US 2013/0017368 and U.S. Patent No. 8,435,599, which are incorporated herein by reference.

PRESSURE-SENSITIVE ADHESIVE

[0073] In one or more embodiments, adhesive layer 17, which is a pressure-sensitive adhesive, is prepared from a holt-melt adhesive, which is an adhesive that can be extruded or otherwise flows when heated to threshold temperatures, and therefore can be applied in the absence of a carrier or solvent. In other embodiments, pressure- sensitive adhesive layer 17 is prepared from a solvent-borne adhesive, which includes those compositions where the solids portion of the adhesive is dissolved or suspended in a solvent, applied to the membrane in the form of a liquid, and the solvent is evaporated to leave the adhesive layer.

[0074] In one or more embodiments, the thickness of pressure-sensitive adhesive layer 17 may be at least 15 μπι, in other embodiments at least 30 μπι, in other embodiments at least 45 μπι, and in other embodiments at least 60 μπι. In these or other embodiments, the thickness of pressure-sensitive adhesive layer 17 may be at most 1000 μπι, in other embodiments at most 600 μπι, in other embodiments at most 300 μπι, in other embodiments at most 150 μπι, and in other embodiments at most 75 μπι. In one or more embodiments, the thickness of pressure-sensitive adhesive layer 17 may be from about 15 μπι to about 600 μπι, in other embodiments from about 15 μπι to about 1000 μΐτι, in other embodiments from about 30 μπι to about 300 μπι, and in other embodiments from about 45 μπι to about 150 μπι.

[0075] In one or more embodiments, especially where the pressure-sensitive adhesive is a hot-melt adhesive, the pressure-sensitive adhesive composition may be characterized as a solid at temperatures below 200 °F, in other embodiments below 190 °F, in other embodiments below 180 °F, and in other embodiments below 170 °F. In these or other embodiments, the pressure-sensitive adhesive composition is characterized as a fluid above 200 °F, in other embodiments above 250 °F, in other embodiments above 300 °F, and in other embodiments above 350 °F.

[0076] Exemplary pressure-sensitive adhesive compositions that may be employed in practicing the present invention include those compositions based upon acrylic polymers, butyl rubber, ethylene vinyl acetate, natural rubber, nitrile rubber, silicone rubber, styrene block copolymers, ethylene-propylene-diene rubber, ataticpolyalpha olefins, and vinyl ether polymers. In combination with these base polymers, the pressure-sensitive adhesive compositions may include a variety of complementary constituents such as, but not limited to, tackifying resins, waxes, antioxidants, and plasticizers.

[0077] In particular embodiments, the pressure-sensitive adhesive compositions of the present invention include polystyrene block copolymers. These block copolymers include at least two types of blocks, which may be referred to as A and B blocks, where the A blocks represent blocks deriving from the polymerization of at least one vinyl aromatic monomer (e.g., styrene) and the B blocks derive from the polymerization of at least one conjugated diene monomer (e.g., butadiene). Exemplary vinyl aromatic monomer includes styrene, p-methylstyrene, a-methylstyrene, and vinylnaphthalene. Examples of conjugated diene monomer include 1,3-butadiene, isoprene, 1,3-pentadiene,

1.3- hexadiene, 2,3- dimethyl- 1 , 3 -butadiene, 2 - ethyl- 1 , 3 -butadiene, 2-methyl-l,3-pentadiene, 3-methyl- 1,3-pentadiene, 4-methyl- 1,3-pentadiene, and

2.4- hexadiene.

[0078] In particular embodiments, the block copolymers include at least two A blocks and at least one B block. For example, the use of A-B-A block copolymers is specifically contemplated. In one or more embodiments, the B block may be hydrogenated. In one or more embodiments, the B block is characterized by at least 75 percent hydrogenation, in other embodiments at least 85 percent hydrogenation, and in other embodiments at least 95 percent hydrogenation, where the percent hydrogenation refers to the number of original double bonds within the block reduced by hydrogenation. For example, a polymer block that is 95 percent hydrogenated includes 5 percent of the original double bonds. In one or more embodiments, the aromatic unsaturation within the A blocks is hydrogenated by less than 25 percent, in other embodiments less than 15 percent, and in other embodiments less than 5 percent.

[0079] In one or more embodiments, each A block has an number average molecular weight of at least 2 kg/mole, in other embodiments at least 5 kg/mole, and in other embodiments at least 25 kg/mole. In these or other embodiments, each A block has an number average molecular weight of less than 125 kg/mole, in other embodiments less than 75 kg/mole, and in other embodiments less than 50 kg/mole.

[0080] In one or more embodiments, each B block has a number average molecular weight of at least 10 kg/mole, in other embodiments at least 30 kg/mole, and in other embodiments at least 50 kg/mole. In these or other embodiments, each A block has an number average molecular weight of less than 250 kg/mole, in other embodiments less than 175 kg/mole, and in other embodiments less than 125 kg/mole.

[0081] Exemplary styrene block copolymers include styrene-butadiene-styrene block copolymer, hydrogenated styrene-butadiene-styrene block copolymer (which may also be referred to as styrene-ethylene/butene-styrene block copolymer), styrene-isoprene- styrene block copolymer, and hydrogenated styrene-isoprene-styrene block copolymer (which may also be referred to as styrene-ethylene/propylene-styrene block copolymer). For ease of description, these polymers may be referred to, respectively, as S-B-S block copolymer, S-E/B-S block copolymer, S-I-S block copolymer, and S-E/P-S block copolymer.

[0082] The polystyrene block copolymer-based, pressure-sensitive adhesive compositions used in this invention may also include a modifying resin. In one or more embodiments, modifying resins include end-block modifying resins and/or mid-block modifying resins. As is known in the art, end-block modifying resins include those resins that modify and/or reinforce the styrene blocks of the block copolymer. It is believed that these end-block modifying resins form pseudo cross links between polymer chains. In one or more embodiments, these end-block resins are characterized by a ring and ball softening point of at least 90 °C, in other embodiments at least 100 °C, in other embodiments at least 110 °C, in other embodiments at least 120 °C, in other embodiments at least 140 °C, and in other embodiments at least 160 °C. Exemplary end- block modifying resins include coumarone-indene resins, poly-a-methylstyrene resins, polystyrene resins, vinyl toluene- a-methylstyrene copolymer resins, and polyindene resins. In these or other embodiments, mid-block modifying resins are employed. As is known in the art, mid-block modifying resins include those resins that modify and/or reinforce the diene blocks of the block copolymer. It is believed that these mid-block modifying resins form pseudo cross links between polymer chains. In one or more embodiments, mid-block modifying resins include aliphatic resins such as pentene-type resins, terpene resins, and cycloaliphatic resins.

[0083] Exemplary polyphenylene ether resins, such as polyphenylene oxide, may also be used. In one or more embodiments, these resins are characterized by an intrinsic viscosity of less than 0.4 dl/g, in other embodiments less than 0.35 dl/g, and in other embodiments less than 0.2 dl/g, when measured in solution in chloroform at 25 °C. Useful polyphenylene ether resins are described in U.S. Patent Nos 3,306,874 and 3,257,375, which are incorporated herein by reference.

[0084] In one or more embodiments, the pressure-sensitive adhesives based upon styrene block copolymers may also include an adhesive promoting resin or tackifying resin. In one or more embodiments, a hydrogenated tackifying resin is employed. These resins include, but are not limited to, petroleum resins, synthetic polyterpenes, resin esters and natural terpenes, and combinations thereof. In certain embodiments, the resin modifiers soften or become liquid at temperatures of about 40° C to about 150° C. In certain embodiments, the resin modifiers have number average molecular weights, as measured by vapor phase osmometry, below that of the polymeric material included in the polymeric film. In certain embodiments, the number average molecular weights of the resin modifiers are less than about 5,000. In other embodiments, the number average molecular weights of the resin modifiers are less than about 1,000. In additional embodiments, the number average molecular weights of the resin modifiers are from about 500 to about 1000.

[0085] In certain embodiments, the resin modifiers have ring and ball softening point of about 20° C to about 160° C. In additional embodiments, resin modifiers have ring and ball softening points of about 40° C to about 160° C. In still other embodiments, resin modifiers have ring and ball softening points of about 50° C to about 160° C.

[0086] Various types of natural and synthetic resins, alone or in admixture with each other, may be used be selected as the resin modifier. Suitable resins include, but are not limited to, natural rosins and rosin esters, hydrogenated rosins and hydrogenated rosin esters, coumarone-indene resins, petroleum resins, polyterpene resins, and terpene- phenolic resins. Specific examples of suitable petroleum resins include, but are not limited to, aliphatic hydrocarbon resins, hydrogenated aliphatic hydrocarbon resins, mixed aliphatic and aromatic hydrocarbon resins, hydrogenated mixed aliphatic and aromatic hydrocarbon resins, cycloaliphatic hydrocarbon resins, hydrogenated cycloaliphatic resins, mixed cycloaliphatic and aromatic hydrocarbon resins, hydrogenated mixed cycloaliphatic and aromatic hydrocarbon resins, aromatic hydrocarbon resins, substituted aromatic hydrocarbons, and hydrogenated aromatic hydrocarbon resins. As used herein, "hydrogenated" includes fully, substantially and at least partially hydrogenated resins. Suitable aromatic resins include aromatic modified aliphatic resins, aromatic modified cycloaliphatic resin, and hydrogenated aromatic hydrocarbon resins. Any of the above resins may be grafted with an unsaturated ester or anhydride to provide enhanced properties to the resin. For additional description of resin modifiers, reference can be made to technical literature, e.g., Hydrocarbon Resins, Kirk-Othmer, Encyclopedia of Chemical Technology, 4th Ed. v.13, pp. 717-743 (J. Wiley & Sons, 1995).

[0087] In one or more embodiments, the tackifier resins include phenol-based resins. Included among the phenol-based resins are phenolic resins. These resins may include reactive phenol resins (also referred to as functionalized phenol resins), as well as unreactive resins. In one or more embodiments, the phenolic resin is a resole resin, which can be made by the condensation of alkyl, substituted phenols, or unsubstituted phenols with aldehydes such as formaldehyde in an alkaline medium or by condensation of bi-functional phenoldialcohols. In one or more embodiments, this condensation reaction occurs in the excess or molar equivalent of formaldehyde. In other embodiments, the phenolic resin may be formed by an acid-catalyzed reaction.

[0088] In one or more embodiments, the tackifier resin is a polybutene polymer or oligomer. In particular embodiments, polybutene oils are employed. Useful polybutene oils include high- viscosity oils that may be characterized by a viscosity at 100 °C of at least 80 est, in other embodiments at least 100 est, or in other embodiments at least 120 est up to, for example, about 700 or 800 est. In these or other embodiments, the high viscosity polybutene oils may be characterized by a molecular weight of at least 1000 g/mole, in other embodiments at least 1200 g/mole, or in other embodiments at least 1300 g/mole up to, for example, 1400 or 1500 g/mole. An exemplary high-viscosity polybutene oil is available under the tradename Indapol H300 (Ineos) or PB32 (Soltex).

[0089] In particular embodiments, the tackifying resins include hydrogenated rosins, esters of rosins, polyterpenes, terpene phenol resins, and polymerized mixed olefins. In one or more embodiments, these resins are liquids at room temperature.

UV-CURABLE HOT-MELT PRESSURE-SENSITIVE ADHESIVE

[0090] In one or more embodiments, pressure-sensitive adhesive layer 17 is a cured pressure-sensitive adhesive. In sub-embodiments thereof, this cured pressure-sensitive adhesive layer is formed from a curable hot-melt adhesive. In other words, and as will be described in greater detail below, a pre-cured adhesive composition is applied to the membrane as a hot-melt composition (i.e. the composition is heat and applied as a flowable composition in the absence or appreciable absence of solvent), and then the composition is subsequently crosslinked (i.e. cured) to form the cured pressure-sensitive layer.

[0091] In one or more embodiments, the cured pressure-sensitive adhesive layer may be an acrylic-based hot-melt adhesive. In one or more embodiments, the adhesive is a polyacrylate such as a polyacrylate elastomer. In one or more embodiments, useful polyacrylates include one or more units defined by the formula: where each Ri is individually hydrogen or a hydrocarbyl group and each R.2 is individually a hydrocarbyl group. In the case of a homopolymer, each Ri and R^, respectively, throughout the polymer are same in each unit. In the case of a copolymer, at least two different Ri and/or two different R2 are present in the polymer chain.

[0092] In one or more embodiments, hydrocarbyl groups include, for example, alkyl, cycloalkyl, substituted cycloalkyl, alkenyl, cycloalkenyl, substituted cycloalkenyl, aryl, substituted aryl, aralkyl, alkaryl, allyl, and alkynyl groups, with each group containing in the range of from 1 carbon atom, or the appropriate minimum number of carbon atoms to form the group, up to about 20 carbon atoms. These hydrocarbyl groups may contain heteroatoms including, but not limited to, nitrogen, oxygen, boron, silicon, sulfur, and phosphorus atoms. In particular embodiments, each R^ is an alkyl group having at least

4 carbon atoms. In particular embodiments, Ri is hydrogen and R2 is selected from the group consisting of butyl, 2-ethylhexyl, and mixtures thereof.

[0093] In one or more embodiments, the polyacrylate elastomers that are useful as adhesives in the practice of this invention may be characterized by a glass transition temperature (Tg) of less than 0 °C, in other embodiments less than -20 °C, in other embodiments less than -30 °C. In these or other embodiments, useful polyacrylates may be characterized by a Tg of from about -70 to about 0 °C, in other embodiments from about -50 to about -10 °C, and in other embodiments from about -40 to about -20 °C.

[0094] In one or more embodiments, the polyacrylate elastomers that are useful as adhesives in the practice of this invention may be characterized by a number average molecular weight of from about 90 to about 800 kg/mole, in other embodiments from about 100 to about 350 kg/mole, in other embodiments from about 100 to about 700 kg/mole, in other embodiments from about 150 to about 270 kg/mole, in other embodiments from about 120 to about 600 kg/mole, and in other embodiments from about 180 to about 250 kg/mole.

[0095] In one or more embodiments, the polyacrylate elastomers that are useful as adhesives in the practice of this invention may be characterized by a Brookfield viscosity at 150 °C of from about 10,000 to about 200,000 cps, in other embodiments from about 30,000 to about 60,000 cps, in other embodiments from about 30,000 to about 170,000 cps, in other embodiments from about 25,000 to about 150,000 cps, in other embodiments from about 30,000 to about 60,000 cps, and in other embodiments from about 40,000 to about 50,000 cps.

[0096] Specific examples of polyacrylate elastomers that are useful as adhesives in the practice of the present invention include poly(butylacrylate), and poly(2- ethylhexylacryalte) . These polyacrylate elastomers may be formulated with photoinitiators, solvents, plasticizers, and resins such as natural and hydrocarbon resins. The skilled person can readily formulate a desirable coating composition. Useful coating compositions are disclosed, for example, in U.S. Patent Nos 6,720,399, 6,753,079, 6,831,114, 6,881,442, and 6,887,917, which are incorporated herein by reference.

[0097] In other embodiments, the polyacrylate elastomers may include polymerized units that serve as photoinitiators. These units may derive from copolymerizable photoinitiators including acetophenone or benzophenone derivatives. These polyacrylate elastomers and the coating compositions formed therefrom are known as disclosed in U.S. Patent Nos 7,304,119 and 7,358,319, which are incorporated herein by reference.

[0098] Useful adhesive compositions are commercially available in the art. For example, useful adhesives include those available under the tradename acResin (BASF), those available under the tradename AroCure (Ashland Chemical), and NovaMeltRC (NovaMelt) . In one or more embodiments, these hot-melt adhesives may be cured (i.e., crosslinked) by UV light.

[0099] In one or more embodiments, the hot-melt adhesive is at least partially cured after being applied to the membrane, as will be discussed in greater detail below. In one or more embodiments, the adhesive is cured to an extent that it is not thermally processable in the form it was prior to cure. In these or other embodiments, the cured adhesive is characterized by a cross-linked infinite polymer network. While at least partially cured, the adhesive layer of one or more embodiments is essentially free of curative residue such as sulfur or sulfur crosslinks and/or phenolic compounds or phenolic-residue crosslinks.

[00100] As indicated above, the pressure-sensitive adhesive, in its cured stated, provides sufficient tack to allow the membrane composites of this invention to be used in roofing systems that meet industry standards for wind uplift. In one or more embodiments, this tack may be quantified based upon the peel strength when adhered to another membrane in accordance with ASTM D- 1876-08. In one or more embodiments, the cured pressure-sensitive adhesive of the present invention is characterized by a peel strength, according to ASTM D-1876-08, of at least 1.8 lbf/in, in other embodiments at least 3.6 lbf/in, in other embodiments at least 8.0 lbf/in, in other embodiments at least 15 lbf/in, and in other embodiments at least 20 lbf/in.

[00101] Similarly, the tack of the pressure-sensitive adhesive, in its cured state, may be quantified based upon the peel strength when adhered to a construction board (e.g. insulation board) having a kraft paper facer in accordance with ASTM D-903-98 (2010). In one or more embodiments, the cured pressure-sensitive adhesive of the present invention is characterized by a peel strength, according to ASTM D-903-98 (2010) using an insulation board with kraft paper facer, of at least 1.5 lbf/in, in other embodiments at least 2.0 lbf/in, in other embodiments at least 2.5 lbf/in, in other embodiments at least 3.0 lbf/in, and in other embodiments at least 3.5 lbf/in.

PREPARATION OF COMPOSITE MEMBRANES

[00102] In one or more embodiments, membrane composites according to the invention can be prepared by using one or more for of the following process steps. These process steps may generally include saturating a fabric with asphaltic material to form a saturated fabric, optionally applying a surface coating to one planar surface of the saturated fabric, applying a layer of pressure-sensitive adhesive to a planar surface of the saturated fabric to form an uncured layer of pressure-sensitive adhesive, optionally curing the layer of pressure-sensitive adhesive to form a layer of cross-linked pressure

's- sensitive adhesive, applying a release member to the layer of pressure-sensitive adhesive to form the membrane composite, and optionally winding the membrane composite to form a roll of the membrane composite.

[00103] Exemplary processes for preparing composite membranes according to the invention can be described with reference to Fig. 6, which shows process 50 including saturation step 51 wherein fabric 52 is submerged into asphaltic tank 54 including asphaltic composition 56 in molten or flowable form. Saturation step 51 provides fabric 52 with an asphaltic coating to form saturated fabric 58. The coating thickness of asphaltic material on saturated fabric 58 may be controlled by calender rolls 60, which are positioned to meet saturated fabric 58 after leaving asphaltic tank 54.

[00104] Following saturation step 51, the saturated fabric 58 may optionally be subjected to surfacing step 61 where optional surfacing agents, such as granules or a polymeric sheet, is applied to a planar surface 62 of saturated fabric 58. In one more embodiments, surfacing step 61 may optionally include further treatment through press or nip rolls 64 to further size sheet 58 and/or imbed or secure surface treatments to the planar surface of sheet 58.

[00105] After optional surfacing step 61, the saturated fabric 58, which may also be referred so as sheet 58, may undergo cooling within a cooling step 71. For example, sheet 58 may be subjected to cooling by traveling on a chilled water bath and/or over cooling drums. In one or more embodiments, cooling step 71 may further include further treatment through press or nip rolls 74 to further size sheet 58 and/or imbed or secure surface treatments received in surfacing step 61.

[00106] Following cooling step 71, sheet 58 is positioned to receive an adhesive layer with an adhesive applying step 81, which may also be referred to as adhesive coating step 81 or simply coating step 81. As shown in Fig. 6, coating step 81 may include the sub-step of heating where, for example, UV-curable hot-melt adhesive 82 is heated to a desired temperature within a heated tank 83. Adhesive 82 is fed into an extrusion device, such as a coater 84, which may include a pump, such as a gear pump 85, and a slot die 86. Within coating step 81, coater 84 extrudes adhesive 82, which is in its molten, liquid or flowable state, and deposits a coating layer 87 of adhesive 82 onto a planar surface 88 of sheet 58. As shown in Fig. 6, coating step 81 can include a roll-coating operation, where adhesive 82 is applied to sheet 58 while sheet 58 is at least partially wound around a coating mandrel 89.

[00107] In one or more embodiments, sub-step of heating heats the adhesive to a temperature of from about 120 to about 160 °C, in other embodiments from about 125 to about 155 °C, and in other embodiments from about 130 to about 150 °C.

[00108] In one or more embodiments, coating step 81 applies an adhesive to the surface of a membrane to form a coating layer of adhesive that has a thickness of at least 2 μπι, in other embodiments at least 5 μπι, in other embodiments at least 10 μπι, and in other embodiments at least 20 μπι. In one or more embodiments, coating step 81 applies an adhesive to the surface of a membrane to form a coating layer of adhesive that has a thickness of from about 2 to about 381 μπι, in other embodiments from about 5 to about 305 μπι, and in other embodiments from about 10 to about 254 μπι. In one or more embodiments, the coating has a uniform thickness such that the thickness of the coating at any given point on the surface of the membrane does not vary by more than 5 μπι, in other embodiments by more than 10 μπι, and in other embodiments by more than 25 μπι.

[00109] Following coating step 81, sheet 58, which now carries adhesive coating layer 87, is fed to a curing step 91, which may be referred to as crosslinking step 91, where coating layer 87 of adhesive 82 is subjected to a desired dosage of curing energy, such as UV radiation 92, which may be supplied by one or more UV lamps 93. UV lamps 93 may include, for example, mercury- type UV lamps or LED UV lamps. As the skilled person appreciates, the desired dosage of UV energy can be supplied to coating 91 by adjusting the UV intensity and exposure time. The intensity can be manipulated by the power supplied to the respective lamps and the height (H) that the lamps are placed above the surface of coating 87 of adhesive 82. Exposure time can be manipulated based upon the line speed (i.e., the speed at which sheet 58 carrying coating layer 87 is passed through UV curing step 91).

[00110] In one or more embodiments, curing step 91 subjects the adhesive coating to a UV dosage of from about 30 to about 380 millijoule/cm^, in other embodiments from about 35 to about 300 millijoule/cm^, in other embodiments from about 40 to about 280 millijoule/cm^, in other embodiments from about 45 to about 240 millijoule/cm2, and in other embodiments from about 48 to about 235 millijoule/cm^. It has advantageously been discovered that the required dosage of energy can be exceeded without having a deleterious impact on the adhesives of the present invention. For example, up to ten times, in other embodiments up to five times, and in other embodiments up to three times the required dosage can be applied to the coating composition without having a deleterious impact on the coating composition and/or its use in the present invention.

[00111] In one or more embodiments, curing step 91 subjects the adhesive coating to a UV intensity, which may also be referred to as UV irradiance, of at least 150, in other embodiments at least 200, and in other embodiments at least 250 milliWatts/cm^. In these or other embodiments, curing step 91 subjects the adhesive coating to a UV intensity of from about 150 to about 500 milliWatts/cm^, in other embodiments from about 200 to about 400 milliWatts/cm^, and in other embodiments from about 250 to about 350 milliWatts/cm^. It has advantageously been discovered that the ability to appropriately cure the coating compositions of the present invention, and thereby provide a useful pressure-sensitive adhesive for the roofing applications disclosed herein, critically relies on the UV intensity applied to the coating. It is believed that the thickness of the coatings (and therefore the thickness of the pressure-sensitive adhesive layer) employed in the present invention necessitates the application of greater UV intensity.

[00112] In one or more embodiments, the energy supplied to the coating layer within curing step 91 is in the form of UV-C electromagnetic radiation, which can be characterized by a wave length of from about 250 to about 260 nm. In one or more embodiments, the UV dosage applied during curing step 91 is regulated based upon a UV measuring and control system that operates in conjunction with curing step 91. According to this system, UV measurements are taken proximate to the surface of the adhesive coating layer using known equipment such as a UV radiometer. The data from these measurements can be automatically inputted into a central processing system that can process the information relative to desired dosage and/or cure states and automatically send signal to various variable-control systems that can manipulate one or more process parameters. For example, the power supplied to the UV lamps and/or the height at which the UV lamps are positioned above the coating layer can be manipulated automatically based upon electronic signal from the central processing unit. In other words, the UV intensity, and therefore the UV dosage, can be adjusted in real time during the manufacturing process.

[00113] Following UV curing step 91, sheet 58, which now carries cured coating 89, may receive release member 102 within release paper application step 101. As shown in Fig. 6, release member 102 may be supplied from a mandrel 103 and removably mated to upper surface 104 of cured coating 89 through pressure supplied by nip rolls 105.

[00114] After application of release member 102 within step 101, the composite product 110 may be subjected to one or more finishing steps such as cutting and winding step. For example, and as shown in Fig. 6, composite 119 may be wound within winding step to provide wound rolls 81 of composite products 83.

[00115] In those embodiments where a barrier layer is applied, the barrier layer is deposited on the asphaltic sheet prior to application of the pressure-sensitive coating composition. As the skilled person will appreciate, this barrier layer can be applied to the asphalt sheet in the form of a film by using standard laminating techniques. Alternatively, the barrier layer can be applied to the asphalt sheet as a liquid coating composition by using standard coating techniques. Or, in other embodiments, the barrier layer can be applied as a hot melt composition by using standard extrusion techniques.

[00116] In other embodiments, the membrane composites of the present invention can be prepared by using film transfer techniques. Generally speaking, these processes provide an asphalt-coated sheet, as described above, and contemporaneously provide a release film carrying a pressure-sensitive adhesive (e.g. a cured pressure-sensitive adhesive). The coated asphalt sheet and the release member carrying the pressure- sensitive adhesive are mated through the pressure-sensitive adhesive to form the composite membrane. [00117] A specific process employing the transfer film technique is shown in Fig. 7 wherein process 110 includes a first subprocess 111 for providing an asphalt-saturated sheet, and a second subprocess 112 for providing a release member carrying a cured pressure-sensitive adhesive. Subprocess 111 may be similar to the processes described above that include, for example, saturation step 51 wherein fabric 52 is submerged into asphaltic tank 54 including asphaltic composition 56 in molten or flowable form. Saturation step 51 provides fabric 52 with an asphaltic coating to form saturated fabric 58. The coating thickness of asphaltic material on saturated fabric 58 may be controlled by calender rolls 60, which are positioned to mate saturated fabric 58 after leaving asphaltic tank 54.

[00118] Following saturation step 51, the saturated fabric 58 may optionally be subjected to surfacing step 61 where optional surfacing agents, such as granules or a polymeric sheet, is applied to a planar surface 62 of saturated fabric 58. In one more embodiments, surfacing step 61 may optionally include further treatment through press or nip rolls 64 to further size sheet 58 and/or imbed or secure surface treatments to the planar surface of sheet 58.

[00119] After optional surfacing step 61, the saturated fabric 58, which may also be referred to as sheet 58, may undergo cooling within a cooling step 71. For example, sheet 58 may be subjected to cooling by traveling on a chilled water bath and/or over cooling drums. In one or more embodiments, cooling step 71 may further include further treatment through press or nip rolls 74 to further size sheet 58 and/or imbed or secure surface treatments received in surfacing step 61.

[00120] Sub-step 112 for providing a release member carrying a cured pressure- sensitive adhesive may include similar processes to those described above. For example, as shown in Fig. 7, sub-step 112 may include providing a roll of release member 113, which is positioned to receive an adhesive layer within an adhesive applying step 81, which may also be referred to as adhesive coating step 81 or simply coating step 81. Coating step 81 may include the sub-step of heating where, for example, UV-curable hot- melt adhesive 82 is fed into an extrusion device, such as a coater 84, which may include a pump, such as a gear pump 85, and a slot die 86. Within coating step 81, coater 84 extrudes adhesive 82, which is in its molten, liquid or flowable state, and deposits a coating layer 87 of adhesive 82 onto a planar surface 114 of release member 113. Coating step 81 can include a roll-coating operation, where adhesive 82 is applied to release member 113 while release member 113 is at least partially wound around a coating mandrel.

[00121] Following coating step 81, release member 113, which now carries adhesive coating layer 87, is fed to a curing step 91, which may be referred to as crosslinking step 91, where coating layer 87 of adhesive 82 is subjected to a desired dosage of curing energy, such as UV radiation 92, which may be supplied by one or more UV lamps 93, as described above. UV lamps 93 may include, for example, mercury-type UV lamps or LED UV lamps. As the skilled person appreciates, the desired dosage of UV energy can be supplied to coating 91 by adjusting the UV intensity and exposure time. The intensity can be manipulated by the power supplied to the respective lamps and the height (H) that the lamps are placed above the surface of coating 87 of adhesive 82. Exposure time can be manipulated based upon the line speed (i.e., the speed at which sheet 58 carrying coating layer 87 is passed through UV curing step 91).

[00122] Within sub-step 115, asphalt-saturated sheet 58 and release member 113 carrying cured adhesive layer 87 are mated at nip rolls 116, 116' to form composite 117, which may be wound within a subsequent winding step to provide roll 118.

[00123] As suggested above, in those embodiments where a barrier layer is applied, the barrier layer may be deposited on the asphaltic sheet prior to application of the pressure-sensitive coating composition. Or, where the composite is prepared by using the film transfer techniques, the barrier layer may be applied to the layer of pressure- sensitive adhesive (e.g. layer of cured pressure-sensitive adhesive), and then this laminate structure can be laminated to the asphaltic body so as to position the barrier layer adjacent to the asphaltic body.

[00124] The skilled person will also appreciate that preparation of the release member carrying a cured pressure-sensitive adhesive and the asphaltic membrane need not take place within the same facility or at the same time. Namely, in one or more embodiments, the release member carrying a cured pressure-sensitive adhesive and the coated asphaltic sheet are separately prepared and then subsequently brought together and laminated to form the composite of the present invention.

CHARACTERISTICS OF COMPOSITE

[00125] In one or more embodiments, the layer of crosslinked pressure-sensitive adhesive disposed on a surface of the asphaltic body according to the present invention may be characterized by an advantageous peel strength. In one or more embodiments, the peel strength of the layer of crosslinked pressure-sensitive adhesive disposed on the asphaltic body of the present invention may be characterized by a peel strength, as determined according to Pressure Sensitive Tape Council (PSTC) 101, of at least 3.0, in other embodiments at least 3.5, and in other embodiments at least 4.0 psi. In these or other embodiments, the peel strength may be from about 3.0 to about 25 in other embodiments from about 3.5 to about 20, and in other embodiments from about 4.0 to about 18 psi.

[00126] In one or more embodiments, the layer of crosslinked pressure-sensitive adhesive disposed on a surface of the asphaltic body according to the present invention may be characterized by an advantageous dead load shear. In one or more embodiments, the dead load shear of the layer of crosslinked pressure-sensitive adhesive disposed on the asphaltic body of the present invention may be characterized by a dead load shear, as determined according to PSTC 107, of at least 0.5 hour (time of failure), in other embodiments at least 1.0 hour, and in other embodiments at least 1.5. In these or other embodiments, the dead load shear may be from about 2.0 to about 2.5 hours. APPLICATION TO A ROOF SURFACE

[00127] The membrane composites of the present invention can advantageously be applied to a roof surface (also known as roof substrate) by using standard peel and stick techniques. For example, the composite can be unrolled on a roof surface and placed into position. Portions of the composite are then typically folded back and portions of the release member are removed. The composite can then subsequently be adhered to the roof surface by using various techniques including the use of rollers and the like to mate the adhesive to the substrate. It has advantageously been discovered that the pressure-sensitive adhesive layer employed in the membranes of the present invention allows the membranes to be adhered to a variety of roofing surfaces. These include, but are not limited to, wood decks, concrete decks, steel decks, faced construction boards, and existing membrane surfaces. In particular embodiments, the composites of the present invention are adhered, through the cured adhesive layer disclosed herein, to a faced construction board such as, but not limited to, polyisocyanurate insulation boards or cover boards that include facers prepared from polar materials. For example, the adhesives of the present invention provide advantageous adhesion to facers that contain cellulosic materials and/or glass materials.

[00128] In one or more embodiments, such as where the adhesive is a cured pressure-sensitive adhesive deriving from a melt-extrudable adhesive composition, it is believed that the polar nature of the adhesive is highly compatible with the polar nature of these facer materials and/or any adhesives or coatings that may be carried by glass or paper facers. Accordingly, embodiments of the present invention are directed toward a roof deck including a construction board having a cellulosic or glass facer and an asphaltic-based composite secured to the construction board.

[00129] An exemplary roof system according to embodiments of the present invention may be described with reference to Fig. 8, which shows roof system 120 including roof deck 122, a layer of construction board 124, which construction boards may include insulation and/ or cover boards, one or more layers of base sheets 126 (e.g. asphaltic-based composites according the present invention), and a layer of cap sheets 128 (e.g. asphaltic-based composites according the present invention). In one or more embodiments, the lower most layer of base sheet of the one or more layers of base sheets 126 is secured to the underlying layer of construction boards 124 through the adhesive layer of the composites according the present invention. In one or more embodiments, any additional layers of base sheets 126 are secured to the underlying base sheets through the adhesive layer of the composites of according the present invention. In these or other embodiments, cap sheet layer 128 is secured to the underlying layer of base sheets 126 through the adhesive layer of the composites according the present invention. In one or more embodiments, a sealant, caulk, or adhesive may be used to secure the lap area between adjoining sheet (e.g. within the side lap or, for example, at a T-joint). As the skilled person will appreciate, a first membrane composite may be secured to the underlying surface through the pressure-sensitive adhesive according the present invention, and then a sealant, caulk, or adhesive may be applied to the composite in the lap area. A second membrane composite, after removal of the release liner, is applied to the roof surface and overlaps the lap area and is mated thereto with the sealant sandwiched within the seam.

[00130] In one or more embodiments, the roof systems of the present invention (e.g. the roof system exemplified in Fig. 8, meet industry standards for flame spread/resistance. In one or more embodiments, the roof system one or more composite membrane layers in accordance with the present invention may be classified as a class A, or in other embodiments class B, roof system according to UL 790, wherein the roof system includes a four-layered asphaltic-based membrane system over a polyisocyanurate insulation board covering a wood deck.

[00131] In one or more embodiments, the roof systems of the present invention (e.g. the roof system exemplified in Fig. 4, meet industry standards for wind uplift. In one or more embodiments, the roof systems employing one or more composite membrane layers in accordance with the present invention can achieve at least a 60, in other embodiments at least a 75, and in other embodiments at least 90 rating according to UL 1897 (as well as UL 590).

[00132] Various modifications and alterations that do not depart from the scope and spirit of this invention will become apparent to those skilled in the art. This invention is not to be duly limited to the illustrative embodiments set forth herein.