MXPA97006591A - Composite roofing members, which have improved dimensional stability and related methods - Google Patents

Abstract

The present invention relates to a composite recovery board (10), comprising a foam core (12) selected from the group consisting of polyisocyanurate and polyurethane materials and mixtures thereof, a coating (15) applied to a main surface ( 13) of the foam core and comprising a sheet selected from the group consisting of reinforced polymer materials and reinforced cellulosic materials, wherein the polymeric materials and the cellulosic materials are reinforced with a material selected from the group consisting of glass strands, Glass fibers and their mixtures and gypsum board (14) applied to the opposite main surface (12) of the foam core. A method for re-roofing a roof, which comprises applying composite recovery boards of the present invention to a roof deck, and applying a weather protective coating on the recovery boards. A continuous method of producing a composite recovery board comprises feeding the gypsum board (14) into a laminating structure (21), depositing a foamable liquid polymer (36) on the gypsum board, feeding a coating material (15) into the gypsum board. laminating structure on the foamable liquid polymer, allowing the liquid polymer to rise between the gypsum board and coating material forming the polymer foam of a predetermined thickness, cure the polymer foam under heat (44) to create the composite board; and cut the composite board in desired stretches

Description

COMPOSITE ROOFING MEMBERS, WHICH HAVE IMPROVED DIMENSIONAL STABILITY AND RELATED METHODS TECHNICAL FIELD This invention relates to a composite board suitable for use as an insulation or recovery board within a roof system. Particularly, the present invention relates to a composite board having improved dimensional stability, especially when exposed to extreme environmental conditions, including high heat, humidity and hygroscopicity. BACKGROUND OF THE INVENTION The construction of ceilings in a low inclination roof, generally consists of a roof platform, an insulating barrier on the platform, a layer of resistance to the environment applied to the insulating layer and optionally a layer of heat-resistant material. The roof platform generally includes materials such as wood, plaster, concrete, steel and the like. On the roof deck, insulation boards or insulators are typically applied to provide thermal insulation and a uniform surface to which the protective layer of the environment is applied. The most common insulating boards are made of polyisocyanurate, and recovery boards are properly made of extruded polystyrene or wood fibers. Polyisocyanurate can be coated with a front or protective coating that can be rigid or flexible and can be flame retardant or flame retardant. In a re-roofing operation, the roof deck can refer to the existing roof, including the existing insulation and the weather-resistant layer. Insulation or recovery boards, as they refer to roofing again, have been used when the existing roof leaks or leaks. These boards generally apply to a built-in roof board, to provide a uniform surface when an existing roof is recovered. The most common recovery boards are made of wood fibers or extruded polystyrene. Wood fibers are typically coated with a thin layer of asphaltic material of the type on the one hand, but extruded polystyrene typically does not contain a coating. To seal the roof of the elements, the insulation or recovery boards are typically covered with various materials including molten asphalt, modified bituminous membrane, rubberized asphalt, or an elastomeric composition, such as EPDM (ethylene-propylene diene monomer). Not all sealing materials mentioned above are compatible with each type of insulation or recovery board. For example, molten asphalt can not be used with extruded polystyrene. Correct combinations of seal material and isolation or recovery board are known to those with skill in the industry.

Finally, the thermally resistant layer of material, which is generally applied directly to the weather-resistant or weather-resistant layer, may include gravel, river stones, foam or a layer of mastic followed by gravel and the like. The application of the protective layer outdoors can be achieved by a number of means, usually dictated by the type of material used. For example, sheets of a protective membrane can be unrolled on the roof and joined together by torch or the use of an adhesive. Although economical and generally widely used, recovery or insulation boards containing wood and polystyrene fibers are often ineffective in hot, humid and hygroscopic environments. Particularly, agglomerated boards of wood fibers will disintegrate in a humid, hygroscopic environment, which is common in a roofing operation again. Polystyrene will undergo expansion, warp or distort in similar environments, especially when exposed to extreme heat on rooftops in hotter climates. The patent literature includes panels and boards used for roofing operations. Constructed roof constructions and their components, for example, are well known in the art. Regarding insulating boards, the patent of the U.S.A. No. 5,001,005, illustrates a rigid foam board comprising a thermoset plastic foam sandwiched between two coatings; the coating comprises glass fibers, non-glass filler and a non-asphalt binder. Likewise, the US patent. No. 4,388,366 illustrates a laminated insulating board comprising a plastic foam core and at least one covering sheet which forms both a protective layer and a venting medium for fluids; the cover sheet comprises the fine glass fibers bonded together with a polyvinyl acetate. The patent of the U.S.A. No. 5,081,810, is directed to a construction panel comprising a core sandwiched between two outer surface layers. The core is formed from polystyrene or polyurethane and the outer surface layers may include plywood or other suitable material. Instead of plywood, the use of other materials such as plaster, has been recognized in the specialty. The patent of the U.S.A. No. 3,512,819 is directed to modular construction wall panels comprising a foamed polyurethane sandwich sandwich between the interior and exterior faces of construction materials, including agglomerated fiberboard, gypsum or plywood. The patent of the U.S.A. No. 3,842,559 is directed to a roof platform construction fabricated from gypsum reinforced with glass fibers. Specifically, the roof platform includes a laminate comprising (i) a gypsum board reinforced with glass fibers, (ii) foamed polyisocyanurate, and (iii) a layer of weather resistant plastic substance. The patent of the U.S.A. No. 4,037,006 is addressed to composite insulated panel boards for use in building construction. The panel board comprises (i) a gypsum board base panel, rigid (ii) a self-adhering layer of foamed plastic and (iii) flame retardant, vapor-moisture resistant edge sheets, covering at the side edges of the plastic foam layer. The patent of the U.S.A. No. 4,052,831, is directed to a panel-based building construction, which can be applied to a roofing system, comprising (i) a rigid board such as plaster and (ii) a foamed plastic insulation layer. The patent of the U.S.A. No. 4,449,336, is directed to a roof structure comprising from the bottom up, (i) steel joints, (ii) ornaments or metal protectors, (iii) a layer of fire-resistant material formed of plasterboard, (iv) a deposit board such as gypsum, (v) an insulating layer, and (vi) a rubber lamination layer. The patent of the U.S.A. No. 5,220,762, is directed to water-resistant gypsum boards, with fibrous mat front. Particularly, one embodiment illustrates a roof platform system that includes (i) a support means, (ii) a water-resistant gypsum board, with fibrous mat front overlying the means, and (iii) a roofing material. exterior finish that superimposes the board. This embodiment may also include an insulating material such as isocyanurate, sandwiched between the support means and the gypsum board. The fibrous web comprises glass fibers and synthetic resin fibers. When a roof platform is contemplated, the finishing material includes asphalt and felt for roofing preceded by the application of a settable cementitious material on the gypsum board with fibrous mat front. In this way, there is still a need for a recovery board that can be exposed to humidity during installation and remain dimensionally stable while wet and during eventual evaporation of moisture. The use of a urethane foam and / or isocyanurate-containing compound between the gypsum board and a coating comprising a polymer such as polypropylene, polymer latices and the like, reinforced with glass strands or glass fibers and optionally a filler , such as calcium carbonate, clay, mica and the like, makes the compound of the present invention dimensionally stable and relatively insensitive to moisture to re-roof. COMPENDIUM OF THE INVENTION Therefore, the object of the present invention is to provide a relatively inexpensive composite board, particularly for use in roofing again, which is dimensionally stable in hot, humid and hygroscopic conditions. Another object of the present invention is to provide a composite board having a coating that can withstand application of the protective layer to the weather on the roof. Another object of the present invention is to provide a composite board that uses gypsum board instead of particle board. Another object of the present invention is to provide a composite board that has sufficient integrity to patch or cover the roof. Another object of the present invention is to provide a composite board which provides a good base for subsequent application of the final layer or roof covering and which is compatible with the latter and the respective means of application. Still another object of the present invention is to provide a method for roofing again using a composite board. Still another objective is to provide a method for manufacturing composite boards of the present invention. Still another object is to provide a method for roofing again, which comprises applying composite boards of the present invention to a roof platform.At least one or more of the above objectives of the present invention in conjunction with their advantages over the foregoing nominees and compounds that will be apparent from the specification that follows, are achieved by the invention as described and claimed below. In general, the present invention provides a composite recovery board comprising a foam core selected from the group consisting of polyisocyanurate and polyurethane materials and mixtures thereof; a coating applied to a main surface of the foam core and comprising a sheet selected from the group consisting of reinforced polymer materials and reinforced cellulosic materials, wherein the polymer materials and the cellulosic materials are reinforced with a material selected from the group It consists of glass strands, glass fibers and their mixtures; and gypsum board applied to the opposite main surface of the foam core. The present invention also includes a method of re-roofing, which comprises applying composite recovery boards to a roof platform, the recovery boards comprising a foam core selected from the group consisting of polyisocyanurate and polyurethane materials and mixtures thereof; and a coating applied to a main surface of the foam core and comprising a sheet selected from the group consisting of reinforced polymer materials and reinforced cellulosic materials, wherein the polymeric materials and the cellulosic materials are reinforced with a material selected from the group that It consists of glass strands, glass fibers and their mixtures; and gypsum board applied to the opposite major surface of the foam core; and apply a protective layer of weather on the recovery boards. Finally, the invention provides a continuous method for producing a composite recovery board comprising the steps of feeding gypsum board into a laminating structure; deposit a foamable polymer liquid on the gypsum board; feeding a coating material in the laminating structure onto the foamable liquid polymer; allowing the liquid polymer to rise between the gypsum board and the coating material to form a polymer foam with a predetermined thickness; cure the polymer foam under heat to create the composite board; and cut the composite board into desired stretches. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a perspective view of a composite roof member and in accordance with the present invention; and Figure 2 is a schematic view of the apparatus used to manufacture roof members of the present invention.

PREFERRED MODALITY FOR CARRYING OUT THE INVENTION The present invention is directed to a composite board or roofing member that is used to re-roof an existing roof. The roofing member is applied to a roof platform that is substantially flat or of low inclination and that can be newly constructed or that is exposed by the removal of the old roof or that is a roof constructed or existing in a condition suitable for recovery. Since the roof platforms are known and do not constitute part of the present invention, apart from a substrate or base on which the roofing members are placed, no further details are necessary. Although roofing members can be used as part of new roof installations, boards are designed specifically for roofing operations again. A common problem in the majority but in all the installations to put ceiling again is a roof or substrate humid and often somewhat deteriorated. Typically, when a leak or runoff is noted, and surely when it is considered necessary to repair, the use of the laminated board of the present invention provides an economical and easy means of roofing again, either in the affected area or most commonly all the ceiling. In this way, the roofing member must have enough integrity to patch or cover the roof; must be able to seal the leak; it must provide a good basis for subsequent application of the final layer or cover, such as EPDM roofing membrane; and must be compatible with the latter and the respective means of application. In other words, a board placed on the old roof to act as a substrate for the new waterproof membrane will typically become wet. Existing boards made from wood fibers, extruded polystyrene will distort and / or deteriorate, requiring greater efforts to put roof back on. Existing boards manufactured from isocyanurate foams will work better, except that the existing state of the art has been to use coatings that also deteriorate, which can lead to untimely board failure. Existing coatings are often reinforced with organic felt materials, which provide an action of capillarity absorption through the coating. While these problems can be minimized by drying the roof before repair, or by waiting for it to dry, this is often not practical. Other coating materials have employed glass reinforcing components and glass fibers bonded together with materials such as urea / formaldehyde resins; however, these "all glass" coatings, as they are sometimes referred to, are notorious for a condition known as "penetration of the leaf causing a spot on the opposite side" (strike through) during the manufacturing process.

When this happens, the foam can penetrate more easily through the coating and reach the lamination equipment causing it to freeze as well as creating other manufacturing problems. This weakness has been attributed somewhat to the use in the polymer industry as binding agents that are porous to allow venting of gases and vapors. Polyvinyl acetate, for example, is often used as the binding agent to provide said porosity in glass reinforced coatings. The composite board according to the present invention is better described with reference to Figure 1. This board is generally indicated by the number 10 and comprises a foam core 11 having first and second major surfaces, lower front 12 and upper front 13 , respectively. Coupling with the lower front 12 of the foam core is a gypsum board 14, while a sheet of coating material 15 is linked to the upper face 13. The composite boards 10 are generally from about 3.81 to 10.16 cm (about 1.5 4"thick), and can be manufactured in different dimensions depending on the intended application Boards manufactured in sheets of 1.22 meters (4 feet wide) and 2.44 meters (8 feet) long, are best suited for compatibility in the industry of the construction.

The foam core 11 may be polyisocyanurate, polyurethane or mixtures thereof. The foam core in general is of standard production and generally includes those that have an approximate index of 250. Particularly, when polyisocyanurate foam is used, those that have an index over 200 are preferred; and when urethane is employed, an index above 120 is preferred. In addition, mixed foams may be employed, such as a mixture of polyisocyanurate and urethane. The nominal density of the polyisocyanurate foams is approximately 32.0 kg / cubic meter (2 pounds per cubic foot) pcf) and approximately 32.0 kg / cubic meter (2 pcf) for polyurethane foams. The topcoat 15 may comprise a reinforced polymer material or reinforced cellulosic material. particularly, the polymer material may include polypropylene, polymer latices or mixtures thereof and the cellulosic material may include recycled paper, cardboard and the like. Examples of polymer / polypropylene latex blends include latices selected from the group consisting of styrene rubber of a butadiene (SBR) polyvinyl chloride and polyvinyl alcohol. Thicknesses of the coatings are typically in the range between approximately .0254 and .381 cm (.01 and .15") .The polymer material also includes reinforcing materials such as glass strands, glass fibers or their mixtures. these reinforcing materials are in the range of about 100 to about 10,000 parts by weight based on 100 parts by weight of the polymer selected to form the coating.More preferably, the reinforcing materials are in the range of about 500 to about 5000 parts by weight, based on 100 parts by weight of the selected polymer to form the coating In addition, the reinforced polymer material may optionally include fillers such as clay, mica, talc, lime, calcium carbonate, gypsum (calcium sulfate) trihydrate of aluminum, antimony oxide, cellulose fibers, plastic polymer fibers and their mixtures, quantities of these fillers are in the range from about 0 to 5000 parts by weight based on 100 parts by weight of the selected polymer to form the coating. Compounds of glass fibers and cellulosic material in conjunction with carbon black and small amounts of agglutination additives can be formed into flat sheets and suitable for use as coating materials. Other coatings include thin sheets of aluminum and thin-foil aluminum trilaminates, kraft paper and thin foil of aluminum can also be used. Instead of particle board or wood fiber base, the present invention replaces a layer of gypsum board 14, which adheres to the lower face 12 of the foam core. A convenient board for this purpose is described in U.S. Pat. No. 5,220,762, the subject of which is incorporated herein by reference. These gypsum boards are manufactured by Georgia-Pacific Corporation and sold under their registered trademark DENS-DECK. Similar gypsum boards will be equally suitable for the practice of the present invention. The advantages include lower costs than wood products and higher resistance to moisture and hygroscopic environments, thus providing vastly improved dimensional stability. The coating of the present invention has been found to impart weather resistance and durability to composite boards used as roof substrates within a constructed ceiling. Particularly the coatings of the present invention have been found to provide dimensional stability to the boards, inhibiting the boards against distortion under high heat and humidity. In addition to dimensional stability, the coating protects the foam against moisture, as well as against penetration. Because of these advantages, the coatings of the present invention have been found particularly useful in recovering boards because the environment commonly found in a roofing operation again is hot humid and often hygroscopic. Furthermore, the optional fillings contribute to the coating resistance and provide the coating with a robust appearance.

The composite boards 10 are typically applied to the roof deck in adjacent parallel and stepped sections that border each other. The boards are generally fastened to the platform by nails or adhesive, although other means for attaching an insulating board to the roof platform are common in the specialty. Once the recovery or composite board of the present invention has been applied to a roof platform, the roof is completed by covering the substrate with a weather protection layer. The protective layer may include asphalt, bitumen, bitumen modified with atactic polypropylene (APP), rubberized asphalt, EPDM roofing membranes or any other conventional protective layer known in the art. In ballasted roofs, this protective layer is then covered with gravel or river stones; where the weight of the river stones serves a second function, which is to attach the protective layer to the roof platform. While the boards can be manufactured in a batch process, a continuous online process is preferred since said process is both efficient and economical. With reference to Figure 2, a continuous process is illustrated schematically in conjunction with the apparatus 20. The apparatus provides a rolling structure, generally 21, which employs continuous belts 24 and 25 connected with at least two of a series of rollers 26 , several of which are directed. Coating material 15 is transported by an upper spool 28 which is placed to feed into the laminating structure 21. The gypsum boards 14 are first fed onto the lower band 25 which is longer than the upper band 24 in order to receive the boards 14. Immediately on a board 14 as it enters the pulse structure 21, a foam mixing head 30 is found. The mixing head 30 is fed from reservoirs 31 and 32 or any amount that are required by the foam composition. select polymer. When the desired foam is a polyurethane, for example the tank 31 can provide the isocyanate components and the tank 32 the polyol components. The resin materials of these deposits are fed through metering pumps 33 and 34 and through appropriate conduits 35 into the mixing head 30 where upon contacting, the reaction begins to form the polymer foam. The mixing head 30 then supplies an appropriate mixture 36 of resins from reservoirs 31 and 32 as well as an amount dosed appropriately on the surface of the moving board 14. Subsequently, downstream of the mixing head 30, the coating 15 is fed to the guide assembly 21, passing around a feed roller 38 which places the coating 15 against the upper band 24. As the board 14, coating 15 and deposited foam composition are transported, the latter amounts, as illustrated at 40, until the covering 15 is in full contact with the upper band 24. It will be appreciated that the bands 24 and 25 are adjustable to allow the desired thicknesses of the board 10. Although the foaming has been completed, the intermediate product, indicated by the number 42 is heated to effect curing of the polymer. This is achieved by properly located heaters, generally 44 or by passage through an oven (not shown). After heating for the appropriate time (residence) and temperature, the product emerges from mills and is cut into sections to produce the boards 10. This cut is within the skill of the specialty, including aerial cutting saws and the like, which provide the desired dimensions without interruption of the apparatus 20. While sections may be varied at will of said apparatus, the widths of the boards 10 may be subsequently cut to size in a separate operation as necessary. It is also possible to provide side walls (not shown) in conjunction with the guide assembly 21, to define the desired widths as the polymer foams inside the laminator. In this way, it will be apparent that the device and methods of the present invention are highly effective in providing useful composite boards for roofing again. The invention is particularly suitable for roofing again, but not necessarily limited to it. The method of the present invention for manufacturing can be practiced with other equipment, and the method for re-roofing can be practiced with the variety of board 10 that fall within the scope of the present invention. Based on the above description, it will now be apparent that the use of the composite boards described herein will carry out the previously established objectives. Therefore, it will be understood that any apparent variations fall within the scope of the claimed invention and thus the selection of the specific component elements can be determined without departing from the spirit of the invention described and illustrated herein. In particular, boards according to the present invention are not necessarily limited to those having a core of polyurethane or isocyanurate foam. Furthermore, as noted above, the composition of the polymer coating can be varied, particularly with the use of optional fillers. In this way, the scope of the invention will include all modifications and variations that fall within the scope of the appended claims.

Claims (18)

1. CLAIMS 1. - A composite recovery board characterized in that it comprises: a foam core selected from the group consisting of polyisocyanurate and polyurethane materials and their mixtures; a coating applied to a core surface of foam core and comprising a sheet selected from the group consisting of reinforced polymer materials and reinforced cellulosic materials, wherein polymeric materials and cellulosic materials are reinforced with a material selected from the group consisting of of glass strands, glass fibers and their mixtures; and gypsum board applied to the opposite main surface of the foam core.
2. 2. A composite board according to claim 1, characterized in that the sheets optionally contain a filling selected from the group consisting of clay, mica, talc, lime or limestone, gypsum, aluminum trihydrate, antimony oxide, fibers of cellulose, plastic polymer fibers and their mixtures.
3. 3. A composite board according to claim 1, characterized in that the foam core comprises polyisocyanurate having an index of 200.
4. 4. A composite board according to claim 1, characterized in that the foam core comprises polyurethane which It has an index over 120.
5. 5. - A composite board according to claim 1, characterized in that the coating has a thickness in the range of approximately .0254 to .381 cm (.01 to .15")
6. 6. - A composite board according to claim 1 , characterized in that the coating comprises the reinforcing material in an amount from about 100 to about 10,000 parts by weight, based on 100 parts by weight of selected polymer to form the coating
7. 7. - A composite board according to claim 1 , characterized in that the polymer materials are selected from the group consisting of polypropylene, polymeric latices and mixtures thereof
8. 8. - A composite board according to claim 7, characterized in that the sheet comprises a mixture of polymer / polypropylene latex, Latex is chosen from the group consisting of including styrene-butadiene rubber, polyvinyl chloride and polyvinyl alcohol. to roof a roof again, characterized in that it comprises: composite recovery board to a roof platform, the recovery boards comprise: a foam core selected from the group consisting of polyisocyanurate and polyurethane materials and their mixtures; and a coating applied to a main surface of the foam core and comprising a sheet selected from the group consisting of reinforced polymer materials and reinforced cellulosic materials, wherein the polymeric materials and the cellulosic materials are reinforced with a material selected from the group that It consists of glass strands, glass fibers and their mixtures; and gypsum board applied to the opposite major surface of the foam core; and apply a protective layer to the weather on the recovery boards. 10. Method for roofing again on a roof, according to claim 9, characterized in that the foam core comprises polyisocyanurate having an index above 200. 11. - Method for roofing again on a roof in accordance with claim 9, characterized in that the foam core comprises polyurethane having an index above 120. 12. - Method for roofing again on a roof according to claim 9, characterized in that the coating has a thickness in the range of about .0254 and .381 cm (.01 to .15") 13. - Method for re-roofing a roof according to claim 1, characterized in that the covering comprises the reinforcing material in an amount of about 100 to approximately 10,000 parts by weight, based on 100 parts by weight of selected polymer to form the coating. 14. - Method for roofing a roof again according to claim 9, characterized in that the polymer materials are selected from the group consisting of polypropylene, polymeric latices and mixtures thereof. 15. Method for roofing a roof again in accordance with claim 14, characterized in that the sheet comprises a mixture of polymer / polypropylene latex, the latex is selected from the group consisting of ethylene-butadiene rubber, polyvinyl and polyvinyl alcohol. 16. - A continuous method for producing a composite recovery board, characterized in that it comprises the steps of: feeding gypsum board to a rolling structure; deposit a foamable liquid polymer on the gypsum board; feeding a coating material on the laminating structure onto the foamable liquid; allow the liquid polymer to rise between the gypsum board and the coating material that forms the polymer foam of a pre-determined thickness; cure the polymer foam under heat to create the composite board; and cut the composite board into desired stretches. 17. Method according to claim 16, characterized in that the coating material comprises a sheet selected from the group consisting of reinforced polymer materials and reinforced cellulosic materials, wherein the polymer materials and the cellulosic materials are reinforced with a material selected from the group consisting of glass strands, glass fibers and their mixtures. 18. Method according to claim 17, characterized in that the polymer materials are selected from the group consisting of polypropylene, polymeric latices and mixtures thereof. SUMMARY OF THE INVENTION The present invention relates to a composite recovery board (10), comprising a foam core (12) selected from the group consisting of polyisocyanurate and polyurethane materials and mixtures thereof; a coating (15) applied to a main surface (13) of the foam core and comprising a sheet selected from the group consisting of reinforced polymer materials and reinforced cellulosic materials, wherein the polymeric materials and the cellulosic materials are reinforced with a material selected from the group consisting of glass strands, glass fibers and their mixtures and gypsum board (14) applied to the opposite main surface (12) of the foam core. A method for roofing a roof again, which comprises applying composite recovery boards of the present invention to a roof platform; and apply a protective layer to the weather on the recovery boards. A continuous method of producing a composite recovery board comprises feeding the gypsum board (14) into a laminating structure (21); depositing a foamable liquid polymer (36) on the gypsum board; feeding a coating material (15) in the laminating structure onto the foamable liquid polymer; allow the liquid polymer to rise between the gypsum board and coating material that forms the polymer foam of a pre-determined thickness; cure the polymer foam under heat (44) to create the composite board; and cut the composite board into desired stretches. RS / frp / 22 / P-138