Patent Description:
Previous attempts at imparting fire repellency involved applied flame retardant compositions to the major surfaces of the cellulosic materials. Flame retardant coating compositions comprising a liquid carrier, a phosphate compound and a metal complexing agent are for example known from JPH11293155. However, such previous attempts resulted in degradation of the aesthetic value of the cellulosic substrate due to the flame retardant compositions interfering with the appearance of the resulting building product. Thus, there is a need for building panels that can be formed from natural materials and exhibit superior cosmetic value without degradation the natural aesthetic appearance imparted by such materials.

Other embodiments of the present invention include a flame-retardant coating composition according to claim <NUM> and to a method of forming a flame-retardant building panel according to claim <NUM>.

The following drawings are for illustration purposes only:.

The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses, being defined by the claims appended hereto.

In the description of embodiments of the invention disclosed herein, any reference to direction or orientation is merely intended for convenience of description and is not intended in any way to limit the scope of the present invention being defined by the claims appended hereto.

According to the present application, the term "substantially free" less than about <NUM> wt.

Referring to <FIG> and <FIG>, a ceiling system <NUM> as well as a building panel <NUM> that may be used in the ceiling system <NUM> are shown, which do not form part of the present invention. The ceiling system <NUM> may comprise at least one or more of the building panels <NUM> installed in an interior space, whereby the interior space comprises a plenum space <NUM> and an active room environment <NUM>. The plenum space <NUM> is defined by the space occupied between a structural barrier <NUM> between floors of a building and the lower major surface <NUM> of the building panel <NUM>. The plenum space <NUM> provides space for mechanical lines within a building (e.g., HVAC, electrical lines, plumbing, telecommunications, etc.). The active space <NUM> is defined by the space occupied beneath the upper major surface <NUM> of the building panel <NUM> for one floor in the building. The active space <NUM> provides room for the building occupants during normal intended use of the building (e.g., in an office building, the active space would be occupied by offices containing computers, lamps, etc.).

Each of the building panels <NUM> may be supported in the interior space by one or more supports <NUM>. Each of the building panels <NUM> are installed such that the upper major surface <NUM> of the building panel <NUM> faces the active room environment <NUM> and the lower maior surface <NUM> of the building panel <NUM> faces the plenum space <NUM>. The building panels <NUM> have superior fire safety performance - particularly when a fire originates in the active room environment <NUM> - without sacrificing the desired aesthetic appearance of the building panel <NUM>, as discussed herein.

Referring to <FIG>, which is not within the scope of the invention as claimed, is a building panel <NUM> having an upper major surface <NUM>, a lower major surface <NUM> that is opposite the upper major surface <NUM>, and major side surfaces <NUM> that extend from the upper major surface <NUM> to the lower major surface <NUM> to form a perimeter of the building panel <NUM>. The major side surfaces <NUM> may comprise first and second longitudinal side surfaces <NUM>, <NUM> extending substantially parallel to each other. The major side surfaces <NUM> may further comprise first and second transverse side surfaces <NUM>, <NUM> extending substantially parallel to each other. The first and second longitudinal side surfaces <NUM>, <NUM> may extend substantially orthogonal to the first and second transverse side surfaces <NUM>, <NUM>.

The building panel <NUM> may have a panel thickness "tp" as measured from the upper major surface <NUM> to the lower major surface <NUM>. The panel thickness tp may range from about <NUM> (<NUM> mils) to about <NUM> (<NUM>,<NUM> mils) - including all values and sub-ranges there-between. In some embodiments, the panel thickness tp may range from about <NUM> (<NUM> mils) to about <NUM> (<NUM> mils) - including all values and sub-ranges there-between. In some embodiments, the panel thickness tp may range from about <NUM> (<NUM> mils) to about <NUM> (<NUM>,<NUM> mils) - including all values and sub-ranges there-between.

The building panel <NUM> may have a panel length "LP" as measured from the first transverse side surface <NUM> to the second transverse side surface <NUM> - i.e., the distance along one of the first or second longitudinal side surfaces <NUM>, <NUM>. The panel length LP may range from about <NUM> (<NUM> inches) to about <NUM> (<NUM> inches) - including all values and sub-ranges there-between. The building panel <NUM> may have a panel width "Wp" as measured from the first longitudinal side surface <NUM> to the second longitudinal side surface <NUM> - i.e., the distance along one of the first or second transverse side surfaces <NUM>, <NUM>. The panel width WP may range from about <NUM> (<NUM> inches) to about <NUM> (<NUM> inches) - including all values and sub-ranges there-between. In some embodiments, the panel width WP may range from about <NUM> (<NUM> inches) to about <NUM> (<NUM> inches) - including all values and sub-ranges there-between.

The building panel <NUM> which is not part of the present invention comprises a body <NUM> having a coating <NUM> applied thereto. The body <NUM> may comprise a first major surface <NUM> opposite a second major surface <NUM> and a side surface <NUM> extending there-between. The body <NUM> may be formed from a cellulosic material (e.g., wood), metal, organic polymer, inorganic polymer, and combinations thereof. The body <NUM> may be formed from a single layer of material (also referred to as an integral structure) or the body <NUM> may have a laminate structure formed from at least two layers. As discussed in greater detail herein, the body <NUM> having a laminate structure may comprise one or more layers of a cellulosic layer <NUM>, a substrate layer <NUM>, and/or an adhesive layer <NUM>. Although not pictured, the coating <NUM> of the present invention may be applied to a non-woven scrim. Non-limiting examples of non-woven scrim include fiberglass non-woven scrims. The non-woven scrim may form at least one of the first or second major surface <NUM>, <NUM> of the building panel <NUM>.

The building panel <NUM> may comprise a decorative pattern <NUM> that is visible from the upper major surface <NUM>, the lower major surface <NUM>, and/or the major side surface <NUM>. The decorative pattern <NUM> may comprise a pattern formed from natural materials, such as cellulosic materials (e.g., wood grain, knots, burl, etc.) or synthetic materials, such as a printed ink. The decorative pattern <NUM> may be a body decorative pattern that exists on one of the first major surface <NUM>, second major surface <NUM>, or side surface <NUM> of the body <NUM>, whereby the body decorative pattern is visible through the coating <NUM>.

The coating <NUM> may be independently applied to each of the first major surface <NUM>, the second major surface <NUM>, and/or the side surface <NUM> of the body <NUM>. In a preferred embodiment, the coating <NUM> is applied to the first major surface <NUM> of the body <NUM> - as shown in <FIG>. In another preferred embodiment, the coating <NUM> may be applied to each of the first major surface <NUM>, the second major surface <NUM>, and the side surface <NUM> of the body <NUM> such that the coating <NUM> encapsulates the body <NUM> - as shown in <FIG> and <FIG>.

The coating <NUM> may be clear or substantially clear. For the purposes of this application, the phrases "substantially clear" or "substantially transparent" refers to materials that have the property of transmitting light in such a way that a normal, human eye (i.e., one belonging to a person with so-called "<NUM>/<NUM>" vision) or a suitable viewing device can see through the material distinctly. The level of transparency should generally be one which permits a normal, human eye to distinguish objects having length and width on the order of at least <NUM>,<NUM> (<NUM> inches), and should not significantly distort the perceived color of the original object. The coating <NUM> should be substantially clear (or substantially transparent) such that the underlying body decorative feature can be visible from the upper major surface <NUM> of the building panel <NUM> as the decorative pattern <NUM> on the overall building panel <NUM>, as discussed further herein. The term "substantially clear" or "substantially transparent" may also refer to the coating having at least <NUM>% optical clarity, whereby <NUM>% optical clarity refers to an underlying surface being completely unhindered visually by the coating <NUM>.

Referring now to <FIG>, the coating <NUM> may comprises an upper coating surface <NUM> opposite a lower coating surface <NUM>. The coating <NUM> may comprise a coating side surface <NUM> that extends from the upper coating surface <NUM> to the lower coating surface <NUM> and forms a perimeter of the coating <NUM>. The coating side surface <NUM> may form a portion of the major side surface <NUM> of the building panel <NUM>. Stated otherwise, the major side surface <NUM> of the building panel <NUM> may comprise the coating side surface <NUM>. The coating <NUM> may have a coating thickness "tc" ranging from about <NUM> (<NUM> mils) to about <NUM> (<NUM> mils) - including all values and sub-ranges there-between - as measured from the upper coating surface <NUM> to the lower coating surface <NUM>. The coating <NUM> may have a coating thickness tc ranging from about <NUM> (<NUM> mils) to about <NUM> (<NUM> mils) - including all values and sub-ranges there-between - as measured from the upper coating surface <NUM> to the lower coating surface <NUM>. The coating <NUM> may have a coating thickness tc ranging from about <NUM> (<NUM> mils) to about <NUM> (<NUM> mils) - including all values and sub-ranges there-between - as measured from the upper coating surface <NUM> to the lower coating surface <NUM>. In some embodiments, the coating <NUM> may have a coating thickness tc ranging from about. <NUM> (<NUM> mils) to about <NUM>,<NUM> (<NUM> mils) - including all values and sub-ranges there-between - as measured from the upper coating surface <NUM> to the lower coating surface <NUM>.

The coating <NUM> may comprise an inorganic composition that is substantially clear. According to the present invention, the phrase "inorganic composition" refers to a dry-state composition having up to about <NUM> wt. % of organic compounds present based on the total dry-weight of the referenced inorganic composition, preferably up to about <NUM> wt. % of organic compounds present based on the total dry-weight of the referenced inorganic composition. According to the present invention, the phrase "inorganic composition" may also refer to a wet-state composition that has up to about <NUM> wt. % of organic compounds present based on the total wet-weight of the referenced inorganic composition, preferably up to about <NUM> wt. % of organic compounds present based on the total wet-weight of the referenced inorganic composition. According to the present invention, the term "inorganic composition" may also refer to a composition that is substantially free of organic polymer.

The phrase "dry-weight" refers to the weight of a referenced component or composition without the weight of any carrier. Thus, when calculating the amounts of components based on dry-weight, the calculation is to be based solely on the solid components (e.g., binder, filler, hydrophobic component, fibers, etc.) and should exclude any amount of residual carrier (e.g., water, VOC solvent) that may still be present from a wet-state, which will be discussed further herein. Additionally, according to the present invention, the phrase "dry-state" refers to a component or composition that is substantially free of carrier, as compared to the phrase "wet-state," which refers to that component still containing various amounts of carrier. The term "weight-state" refers to a component or composition that further comprises a carrier. Similarly, the phrase "wet-weight" refers to a total weight of component or composition that includes the weight of the carrier when in the wet-state.

The inorganic composition may be a glass-forming composition. According to the present invention, a "glass-forming composition" comprises a phosphate component and a complexing agent, whereby the phosphate component reacts to form an inorganic glass-like surface when exposed to elevated temperatures - such as elevated temperatures during a fire.

The phosphate component and the complexing agent may be present in the inorganic coating in a weight ratio ranging from about <NUM>:<NUM> to about <NUM>:<NUM> - including all ratios and sub-ranges there-between. In a preferred embodiment, the phosphate component and the complexing agent may be present in the inorganic coating in a weight ratio ranging from about <NUM>:<NUM> to about <NUM>:<NUM> - including all ratios and sub-ranges there-between.

The phosphate component may be present in an amount ranging from about <NUM> wt. % to about <NUM> wt. % - including all wt. % and sub-ranges there-between - based on the total weight of the inorganic composition in the dry-state. In a preferred embodiment, the phosphate component may be present in an amount ranging from about <NUM> wt. % to about <NUM> wt. % - including all wt. % and sub-ranges there-between - based on the total weight of the inorganic composition in the dry-state.

The complexing agent may be present in an amount ranging from about <NUM> wt. % to about <NUM> wt. % - including all wt. % and sub-ranges there-between - based on the total weight of the inorganic composition in the dry-state. In a preferred embodiment, the complexing agent may be present in an amount ranging from about <NUM> wt. % to about <NUM> wt. % - including all wt. % and sub-ranges there-between - based on the total weight of the inorganic composition in the dry-state.

Non-limiting examples of the phosphate component include phosphoric acid (H<NUM>PO<NUM>), pyrophosphoric acid (H<NUM>P<NUM>O<NUM>), polyphosphoric acid, sodium phosphate, potassium phosphate, aluminum tris (dihydrogen phosphate), other phosphate-ion forming compounds, and combinations thereof.

The complexing agent may use metal-containing complexes in which there is associated with a metal ion one or more phosphate or arsenate ligands and one or more organic ligands, the organic ligands being derived from organic compounds containing an electron-donating oxygen atom or their thio-equivalents. The organic compounds may be hydroxyl compounds, especially alcohols; carbonyl compounds including aldehydes, ketones and esters; nitro compounds and ethers including cyclic ethers. In a non-limiting example, the organic ligand may be lower monohydric alcohols ROH containing <NUM> to <NUM> carbon atoms, esters of the structure R<NUM> COOR<NUM> where R, R<NUM>, and R<NUM> are alkyl groups or substituted alkyl groups containing from <NUM> to <NUM> carbon atoms each, ethers or ketones of the structure R<NUM> -O-R<NUM> or R<NUM> -CO-R<NUM> nitro compounds of the formula R<NUM> NO<NUM>, where R<NUM> and R<NUM> have the meaning ascribed above, and ethers of the structure OR<NUM> where R<NUM> is a divalent alkyl group having up to <NUM> carbon atoms one of which may be replaced by a oxygen atom.

The metal ion in the complexing agent of the present invention may be selected from iron, aluminum, zirconium, vanadium, zinc, manganese, titanium, chromium, and cobalt. In a preferred embodiment, the metal in the complexing agent is iron.

The complexing agent of the present invention may contain the metal ion in an amount ranging from about <NUM> wt. % to about <NUM> wt. % based on the total weight of the complexing agent - including all weight percentages and sub-ranges there-between. In a preferred embodiment, the complexing agent of the present invention contains the metal ion in an amount ranging from about <NUM> wt. % to about <NUM> wt. % based on the total weight of the complexing agent - including all weight percentages and sub-ranges there-between.

As a result, the combination of phosphate component and complexing agent in the present invention results in a weight ratio of phosphate component to metal ion that ranges from about <NUM>,<NUM>:<NUM> to about <NUM>,<NUM>:<NUM> - including all ratios and sub-ranges there-between. When the metal ion is iron, the weight ratio is prereably at least about <NUM>,<NUM>:<NUM>. In a preferred embodiment, the weight ratio of phosphate component to the metal ion may range from about <NUM>,<NUM>:<NUM> to about <NUM>,<NUM>:<NUM> - including all ratios and sub-ranges there-between. In an even more preferred embodiment, the weight ratio of phosphate component to the metal ion may range from about <NUM>,<NUM>:<NUM> to about <NUM>,<NUM>:<NUM> - including all ratios and sub-ranges there-between.

Upon exposure to elevated temperatures, the phosphate component reacts to form a phosphoborate glass layer (also referred to as the "glass layer"). The glass layer forms a hard protective and heat-insulative barrier that is especially helpful in preventing the body <NUM> from igniting at elevated temperatures, for example when the body <NUM> is formed from a cellulosic material as discussed further herein. The heat-insulative barrier formed by the coating <NUM> is especially useful when the upper major surface <NUM>, lower major surface <NUM>, and/or side surface <NUM> of the building panel <NUM> is exposed to heat from a fire that exists in the active room environment <NUM> of the ceiling system <NUM> (as shown in <FIG>). The heat-insulative barrier created by the inorganic composition slows and prevents further propagation of heat and flame through the coating <NUM> and, therefore, through the rest of the body <NUM> of the building panel <NUM>.

According to the present invention, it has been surprisingly discovered that the addition of the metal complexing agent reduces the temperature needed to achieve proper cross-linking and form the glass layer. As discussed further herein, the addition of the metal-complexing agent reduced the temperature needed to sufficiently cure the inorganic composition to less than about <NUM>,<NUM> (<NUM> °F), preferably less than about <NUM> (<NUM> °F) - while still achieving the requisite hardness and adhesion characteristics needed for the coating composition to function properly as a protected layer on a building panel. The added surprising benefit of such lower cure temperatures is that the inorganic coating composition can be cured after application to a cellulosic body <NUM> without substantial risk of causing any heat damage to the cellulosic body <NUM> during cure. Thus, the present invention provides an unexpected discovery in not only reducing the temperature needed to form protective, flame-resistant inorganic coatings, but also provides a method of preserving cellulosic bodies from being damaged due to excessive heat during manufacture.

The inorganic composition may optionally comprise other additives or fillers such as, but not limited to fire retarding compounds (also referred to as "flame retardant"), adhesion promoters, viscosity modifying agents, wetting agents, catalyst, cross-linkers, and ultra-violet stabilizers. According to some embodiments, the inorganic composition may further comprise organic compounds so long as the overall inorganic composition includes less than <NUM> wt. % of organic compounds in the overall inorganic composition. According to some embodiments, the inorganic composition may be substantially free of blowing-agent.

The wetting agent may be non-ionic. The wetting agent may be a linear oxyalkylene alcohol. In a preferred embodiment, the wetting agent may be propoxylated ethoxylated linear alcohol. The wetting agent may be present in a non-zero amount that is less than about <NUM> wt. % - based on the total dry-weight of the inorganic composition. The wetting agent may have a density of about <NUM>/cm<NUM>.

The filler may be present in the inorganic coating in an amount ranging from about <NUM> wt. % to about <NUM> wt. % - including all amounts and sub-range there-between - based on the total dry weight of the inorganic coating. Non-limiting examples of filler may include calcium carbonate (CaCO<NUM>), aluminum carbonate (A1<NUM>(CO<NUM>)<NUM>), lithium carbonate (LiCO<NUM>), magnesium carbonate (MgCO<NUM>), fumed silica, aluminum oxide (Al<NUM>O<NUM>), and combinations thereof.

The flame retardants may be present in the coating <NUM> in an amount ranging from about <NUM> wt. % to about <NUM> wt. % - including all values and sub-ranges there-between - based on the total weight of the coating <NUM>. Non-limiting examples of flame retardant may include ammonium hydroxide, magnesium hydroxide, huntite, hydromagnesite, silica, polyphosphate, chloride salts - such as sodium chloride, antimony oxide, and borates, such as calcium borate, magnesium borate, zinc borate, and combinations thereof.

A non-limiting example of viscosity modifying agent may include hydroxyethyl cellulose, bentonite, polyacrylic rheology modifier, polyurethane rheology modifier, silica, and combination thereof. Hydroxyethyl cellulose is an organic compound - therefore, the hydroxyethyl cellulose may be present in the inorganic composition in an amount that ranges from a non-zero amount to less than <NUM> wt. % based on the total dry-weight of the inorganic composition. In a preferred embodiment, the hydroxyethyl cellulose may be present in the inorganic composition in an amount that ranges from a non-zero amount to less than <NUM> wt. % based on the total dry-weight of the inorganic composition.

The inorganic composition may further comprise a cross-linker that facilitates curing of the coating at lower temperatures. Non-limiting example of cross-linker include triethanolamine, polyol, amine or polyamine, as well as other suitable crosslinker that do not inhibit film formation of the coating. In a preferred embodiment, the crosslinker comprises triethanolamine, which is an organic compound. Therefore, the triethanolamine may be present in the inorganic composition in an amount that ranges from a non-zero amount to less than <NUM> wt. % based on the total wet-weight of the inorganic composition (i.e., before cross-linking). In a preferred embodiment, the triethanolamine may be present in the inorganic composition such that the total organic content ranges from a non-zero amount to less than <NUM> wt. % based on the total wet-weight of the inorganic composition.

The inorganic coating may further comprise borate components that include one or more of boron trioxide (B<NUM>O<NUM>), zinc borate, and other soluble borate forming compound at pH between <NUM> and <NUM>, and combinations thereof. Several variants of zinc borate exist and include Zinc borate Firebrake ZB (2ZnO. <NUM> B<NUM>O<NUM>-<NUM><NUM>O), Zinc borate Firebrake <NUM> (2ZnO. <NUM> B<NUM>O<NUM>), Zinc borate Firebrake <NUM> (4ZnO·B<NUM>O<NUM>·H<NUM>O), ZB-<NUM> (4ZnO·6B<NUM>O<NUM>·<NUM><NUM>O), and ZB-<NUM> (2ZnO·2B<NUM>O<NUM>·<NUM><NUM>O). According to some embodiments the zinc borate may also serve as a fungicide.

According to the present invention, the coating <NUM> may be comprised of a single integral layer (<FIG>) or a plurality of sub-layers <NUM>, <NUM>, <NUM> (<FIG> and <FIG>). The coating <NUM> show in <FIG> having a single integral layer comprises the inorganic composition of the present invention.

Referring now to <FIG>, the coating <NUM> of the present invention may comprise a first sub-layer <NUM> and a second sub-layer <NUM>, whereby the first sub-layer <NUM> is directly atop one or more of the first major surface <NUM>, second major surface <NUM>, and/or side surface <NUM> of the body <NUM>. The second sub-layer <NUM> may be directly atop the first sub-layer <NUM>. The second sub-layer <NUM> comprises the inorganic composition of the present invention. In such embodiments, the inorganic composition may be present in an amount ranging from about <NUM> wt. % to about <NUM> wt. % - including all values and sub-ranges there-between - based on the total dry-weight of the second sub-layer <NUM>.

Referring now to <FIG>, the coating <NUM> of the present invention may comprise a first sub-layer <NUM>, a second sub-layer <NUM>, and a third sub-layer <NUM>, whereby the first sub-layer <NUM> is directly atop one or more of the first major surface <NUM>, second major surface <NUM>, and/or side surface <NUM> of the body <NUM>. The second sub-layer <NUM> may be directly
atop the first sub-layer <NUM>, and the third sub-layer <NUM> may be directly atop the second sub-layer <NUM>. The second sub-layer <NUM> may comprise the inorganic composition of the present invention. In such embodiments, the inorganic composition may be present in an amount ranging from about <NUM> wt. % to about <NUM> wt. % - including all values and sub-ranges there-between - based on the total dry-weight of the second sub-layer <NUM>.

According to the present invention, the first sub-layer <NUM> may also be referred to as a "base coating. " The first sub-layer <NUM> may be an organic coating. According to the present invention, the term "organic coating" refers to a coating in the dry-state that comprises at least <NUM> wt. % of organic compounds based on the total weight of the referenced organic coating in the dry-state, preferably at least <NUM> wt. % of organic compounds based on the total weight of the referenced organic coating in the dry-state.

The first sub-layer <NUM> may comprise a polymer binder in an amount ranging from about <NUM> wt. % to about <NUM> wt. % - including all values and sub-ranges there-between - based on the total dry-weight of the first sub-layer <NUM>.

The polymer binder may comprise polymer produced from unsaturated monomers. Specifically, the polymer may be a homopolymer or copolymer produced from ethylenically unsaturated monomers, such as styrene, alpha-methylstyrene, polymethylsiloxane, vinyl toluene, ethylene, propylene, vinyl acetate, vinyl chloride, vinylidene chloride, acrylonitrile, acrylamide, methacrylamide, acrylic acid, methacrylic acid, (meth)acryloxy-propionic acid, itaconic acid, aconitic acid, maleic acid, monomethyl maleate, monomethyl fumarate, monomethyl itaconate, various (C<NUM>-C<NUM>) alkyl or (C<NUM>-C<NUM>) alkenyl esters of (meth)acrylic acid, various lacquers, latex-based binders and the like. The expression (meth)acrylic, as used herein, is intended to serve as a generic expression embracing both acrylic and methacrylic acid and esters thereof e.g., methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, <NUM>-ethyl hexyl(meth)acrylate, benzyl (meth)acrylate, lauryl (meth)acrylate, oleyl (meth)acrylate, palmityl (meth)acrylate, stearyl (meth)acrylate and the like. In other embodiments, the coating polymer binder may include polymer comprising polyurethane, polyester, polyester-modified polyurethane, or a combination thereof.

The polymer binder of the first sub-layer <NUM> may have a glass transition temperature Tg ranging from about - <NUM> (<NUM> °F) to about <NUM> (<NUM> °F) - including all values and sub-ranges there-between.

The first sub-layer <NUM> may further comprise one or more nonionic surfactants in the amount of <NUM>. % to about <NUM> wt. % - based on the total dry-weight of the first sub-layer <NUM> - including all amount and sub-ranges there-between. The nonionic surfactant component can be a single surfactant or a mixture of two or more nonionic surfactants, the mixture having appropriate HLB values. Suitable nonionic surfactants include but are not limited to ethoxylated nonylphenols, ethoxylated alcohols, ethoxylated castor oil, polyethylene glycol fatty acid esters, and ethyleneglycol-propyleneglycol copolymers. The contemplated nonionic surfactants include ethoxylated nonylphenols and polyethylene glycol fatty acid esters.

The second sub-layer <NUM> may be an inorganic coating that comprises the inorganic glass-forming composition of the present invention. The second sub-layer <NUM> may be a combination of multiple coatings of the inorganic glass-forming composition. The second sub-layer <NUM> may be substantially clear. According to the present invention, the phrase "inorganic coating" refers to the coating having less than <NUM> wt. % of organic compounds present based on the total dry weight of the referenced inorganic coating, preferably less than <NUM> wt. % of organic compounds present based on the total weight of the referenced inorganic coating in the dry-state. According to some embodiments, the inorganic coating of the second sub-layer <NUM> may be formed entirely from the inorganic composition of the present invention.

The third sub-layer <NUM> may be referred to as "topcoat. " The third sub-layer <NUM> may be an inorganic coating according to the present invention or an organic coating. The third sub-layer <NUM> may comprise a sealant composition. The sealant composition may comprise a sealant polymer binder and a flame retardant. Referring now to <FIG>, other embodiments provide that the coating <NUM> may further comprise a third sub-layer <NUM> atop the second sub-layer <NUM>, which is atop the first sub-layer <NUM> that is atop the cellulosic layer <NUM>. The third sub-layer <NUM> may be formed from a moisture barrier composition that imparts moisture barrier properties to the resulting third sub-layer <NUM>. The moisture barrier composition may be comprised of hydrophobic polymeric binder, which may or may not be cross-linked, as well as various additives and fillers.

The sealant polymer binder may be present in an amount ranging from about <NUM> wt. % to about <NUM> wt. % - including all values and sub-ranges there-between - based on the total weight of the sealant composition in the dry-state. The flame retardant may be present in the cellulosic-layer sealant composition in an amount ranging from about <NUM> wt. % to about <NUM> wt. % - including all values and sub-ranges there-between - based on the total dry-weight of the cellulosic-layer sealant composition.

The sealant polymer binder may comprise one or more vinyl or acrylic homopolymers or copolymers formed from ethylenically unsaturated monomers such as ethylene or butadiene and vinyl monomers such as styrene, vinyl esters such as vinyl acetate, vinyl propionate, vinyl butyrates, acrylic acid, methacrylic acid, or esters of acrylic acid and/or esters of methacrylic acid. The esters of acrylic or methacrylic acid may have an alkyl ester portion containing <NUM> to <NUM> carbon atoms as well as aromatic derivatives of acrylic and methacrylic acid, and can include, for example, acrylic and methacrylic acid, methyl acrylate and methyl methacrylate, ethyl acrylate and ethyl methacrylate, butyl acrylate and butyl methacrylate, propyl acrylate and propyl methacrylate, <NUM>-ethyl hexyl acrylate and <NUM>-ethyl hexyl methacrylate, cyclohexyl acrylate and cyclohexyl methacrylate, decyl acrylate and decyl methacrylate, isodecyl acrylate and isodecyl methacrylate, benzyl acrylate and benzyl methacrylate and various reaction products such as butyl, phenyl, and cresyl glycidyl ethers reacted with acrylic and methacrylic acids. In a preferred embodiment, the sealant binder comprises a self-crosslinking acrylic binder. Non-limiting examples of hydrophobic polymeric binder produced from unsaturated monomers. Specifically, the hydrophobic polymer may be a homopolymer or copolymer produced from ethylenically unsaturated monomers, such as styrene, alpha-methylstyrene, vinyl toluene, ethylene, propylene, vinyl acetate, vinyl chloride, vinylidene chloride, acrylonitrile, acrylamide, methacrylamide, acrylic acid, methacrylic acid, (metli)acryloxy-propionic acid, itaconic acid, aconitic acid, maleic acid, monomethyl maleate, monomethyl fumarate, monomethyl itaconate, various (C<NUM>-C<NUM>) alkyl or (C<NUM>-C<NUM>) alkenyl esters of (meth)acrylic acid and the like. The expression (meth)acrylic, as used herein, is intended to serve as a generic expression embracing both acrylic and methacrylic acid and esters thereof e.g., methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, <NUM>-ethyl hexyl(meth)acrylate, benzyl (meth)acrylate, lauryl (meth)acrylate, oleyl (meth)acrylate, palmityl (meth)acrylate, stearyl (meth)acrylate and the like. In other embodiments, the hydrophobic polymeric binder may include polymer comprising polyurethane, polyester, polyester--modified polyurethane, epoxy or a combination thereof.

The hydrophobic polymer may be present in an amount ranging from about <NUM> wt. % to about <NUM> wt. % - including all values and sub-ranges there-between - based on the total weight of the moisture barrier composition.

The flame retardant of the first sub-layer <NUM> may include ammonium hydroxide, magnesium hydroxide, huntite, hydromagnesite, silica, polyphosphate, melamine cyanurate, chloride salts - such as sodium chloride, antimony oxide, and borates, such as calcium borate, magnesium borate, zinc borate, and combinations thereof.

Generally, the coating <NUM> may be applied directly to one of the first major surface <NUM>, second major surface <NUM>, and/or side surface <NUM> of the body <NUM>, optionally with the addition of a carrier such as water. The coating <NUM> - including each sub-layer <NUM>, <NUM>, <NUM> - may be applied by spray, roll-coating, dip coating, curtain coating, brushing, blade coating, or the like, followed by drying and/or curing (optionally with the addition of heat) for a period of time to form the coating <NUM> atop the cellulosic layer <NUM> - as discussed in greater detail herein.

The first sub-layer <NUM> may be applied in the wet-state directly to at least one of the first major surface <NUM>, second major surface <NUM>, and/or side surface <NUM> of the body <NUM>. In the wet-state, the first sub-layer <NUM> may comprise a carrier in an amount ranging from about <NUM> wt. % to about <NUM> wt. % - including all values and sub-ranges there-between - based on the total weight of the wet-state first sub-layer <NUM>. In the wet-state, the first sub-layer <NUM> may be applied in an amount such that the first sub-layer <NUM> has a wet thickness ranging from about <NUM> (<NUM> mils) to about <NUM> (<NUM> mils) - including all values and sub-ranges there-between. The carrier may be selected from water, an organic solvent, or a combination thereof. In a preferred embodiment, the wet-state sealant composition is a waterborne system having a carrier of water and a low VOC (i.e., volatile organic compound) content - i.e. substantially free of VOC solvents. The first sub-layer <NUM> in the wet-state may then be cured or dried (optionally with the addition of heat) for a first-time period, thereby forming the first sub-layer <NUM> atop the body <NUM>.

The resulting first sub-layer <NUM> may comprise a first sub-layer upper surface <NUM> and a first sub-layer lower surface <NUM> opposite the first sub-layer upper surface <NUM>. The first sub-layer <NUM> may have a first sub-layer thickness "tci" as measured from the first sub-layer upper surface <NUM> to the first sub-layer lower surface <NUM>. The first sub-layer thickness tC1 may range from <NUM> (<NUM> mils) to <NUM> (<NUM> mils) - including all values and sub-ranges there-between. The first sub-layer <NUM> may comprise a first sub-layer side surface <NUM> that extends from the first sub-layer
upper surface <NUM> to the first sub-layer lower surface <NUM> and forms a perimeter of the first sub-layer <NUM>.

As previously discussed, the body <NUM> may be formed from a cellulosic material, which comprises pores. Thus, once the first sub-layer <NUM> is applied to one of the first major surface <NUM>, second major surface <NUM>, and/or side surface <NUM> of the body <NUM>, at least a portion of the first sub-layer <NUM> may penetrate into and seal the pores in a direct extending from one of the first major surface <NUM>, second major surface <NUM>, and/or side surface <NUM> of the body <NUM> toward the center of the body <NUM>. The first sub-layer <NUM> in the wet-state may then be dried, optionally, at an elevated temperature, thereby rendering the first sub-layer <NUM> in the dry state.

The second sub-layer <NUM> may be formed by directly applying the previously discussed inorganic composition in the wet-state to the first sub-layer upper surface <NUM> of the first sub-layer <NUM>. In the wet-state, the second sub-layer <NUM> may be applied in an amount such that the second sub-layer <NUM> has a wet thickness ranging from about <NUM> (<NUM> mils) to about <NUM> (<NUM> mils) - including all values and sub-ranges there-between.

The inorganic composition may then be dried (optionally with the addition of heat) for a second-time period of time, thereby forming the second sub-layer <NUM> atop the first sub-layer <NUM>. The resulting second sub-layer <NUM> may comprise a second sub-layer upper surface <NUM> and a second sub-layer lower surface <NUM> opposite the second sub-layer upper surface <NUM>. The second sub-layer <NUM> in the wet-state may be dried at a temperature ranging from about <NUM>,<NUM> (<NUM> °F) to about <NUM>,<NUM> (<NUM> °F) - including all temperatures and sub-ranges there-between. The addition of the metal-complexing agent of the present invention may result in the second sub-layer <NUM> being cross-linked a temperature ranging from about <NUM>,<NUM> (<NUM> °F) to about <NUM>,<NUM> (<NUM> °F) - including all temperatures and sub-ranges there-between. In a preferred embodiment, the second sub-layer <NUM> may be cross-linked at a temperature of about <NUM>,<NUM> (<NUM> °F) to about <NUM> (<NUM> °F) - including all temperatures and sub-ranges there-between.

The second sub-layer <NUM> may have a second sub-layer thickness "tC2" as measured from the second sub-layer upper surface <NUM> to the second sub-layer lower surface <NUM>. The second sub-layer thickness tC2 may range from about <NUM>,<NUM> (<NUM> mils) to about <NUM>,<NUM> (<NUM> mils). The second sub-layer <NUM> may comprise a second sub-layer side surface <NUM> that extends from the second sub-layer upper surface <NUM> to the second sub-layer lower surface <NUM> and forms a perimeter of the second sub-layer <NUM>.

The first sub-layer side surface <NUM> and the second sub-layer side surface <NUM> may form at least a portion of the coating side surface <NUM>. Stated otherwise, the coating side surface <NUM> may comprise the first sub-layer side surface <NUM> and the second sub-layer side surface <NUM>. The overall coating thickness tC of coating <NUM> may be the summation of the first sub-layer thickness tC1 and the second sub-layer thickness tC2 - as follows: <MAT>.

According to these embodiments, the first sub-layer lower surface <NUM> of the first sub-layer <NUM> may contact the upper cellulosic surface <NUM> of the cellulosic layer <NUM>. The first sub-layer upper surface <NUM> may contact the second sub-layer lower surface <NUM> of the second sub-layer <NUM>. The second sub-layer upper surface <NUM> may form at least part of the upper coating surface <NUM> of the coating <NUM>. The first sub-layer lower surface <NUM> may form at least part of the lower coating surface <NUM> of the coating <NUM>. The second sub-layer upper surface <NUM> may form at least part of the upper major surface <NUM> of the building panel <NUM>.

The first sub-layer <NUM> may form a physical barrier that at least partially separates the body <NUM> from the second sub-layer <NUM>. The physical barrier formed by the first sub-layer <NUM> may prevent at least some of the second sub-layer <NUM> (which comprises the glass-forming composition) from penetrating into the body <NUM> (e.g., a cellulosic body <NUM> having porous surfaces). According to some embodiments, the glass heat-insulative barrier that is created by glass-forming composition of the second sub-layer <NUM> may be separated from at least one of the first major surface <NUM>, second major surface <NUM>, and/or side surface <NUM> of the body <NUM> by a distance equal to the first sub-layer thickness tC1.

The third sub-layer <NUM> may be formed by applying the moisture barrier composition with the addition of one or more organic solvents. Non-limiting examples of organic solvents include toluene, ethanol, acetone, butyl acetate, methyl ethyl ketone, ethyl <NUM>-ethoxypropionate. The barrier composition may be present relative to the organic solvent in a weight ratio ranging from about <NUM>:<NUM> to about <NUM>:<NUM>. After application to the second sub-layer upper surface <NUM>, the moisture barrier composition may be dried for a third period of time, optionally at an elevated temperature, sufficient to drive off any organic solvent. The resulting third sub-layer <NUM> may be a continuous or discontinuous coating having a third sub-layer upper surface <NUM> and a third sub-layer lower surface <NUM> opposite the third sub-layer upper surface <NUM>.

In the wet-state, the third sub-layer <NUM> may be applied in an amount such that the third sub-layer <NUM> has a wet thickness ranging from about <NUM> (<NUM> mils) to about <NUM> (<NUM> mils) - including all values and sub-ranges there-between. After drying, the third sub-layer <NUM> in the dry-state may have a third sub-layer thickness "tC3" as measured from the third sub-layer upper surface <NUM> to the third sub-layer lower surface <NUM>. The third sub-layer thickness tC3 may range from about <NUM> (<NUM> mils) to about <NUM> (<NUM> mils). The third sub-layer <NUM> may comprise a third sub-layer side surface <NUM> that extends from the third sub-layer upper surface <NUM> to the third sub-layer lower surface <NUM> and forms a perimeter of the second sub-layer <NUM>.

According to such embodiments, the overall coating thickness tc of coating <NUM> may be the summation of the first sub-layer thickness tci, the second sub-layer thickness tC2, and the third sub-layer thickness tC3 - as follows: <MAT>.

According to these other embodiments, the first sub-layer lower surface <NUM> of the first sub-layer <NUM> may contact the upper cellulosic surface <NUM> of the cellulosic layer <NUM>. The first sub-layer upper surface <NUM> may contact the second sub-layer lower surface <NUM> of the second sub-layer <NUM>. The second sub-layer upper surface <NUM> may contact the third sub-layer lower surface <NUM> of the second sub-layer <NUM>. The third sub-layer upper surface <NUM> may form at least part of the upper coating <NUM> of the coating <NUM>. The first sub-layer lower surface <NUM> may form at least part of the lower coating surface <NUM> of the coating <NUM>. The third sub-layer upper surface <NUM> may form at least part of the upper major surface <NUM> of the building panel <NUM>.

According to other embodiments, the coating <NUM> may comprise only the second sub-layer <NUM> and the third sub-layer <NUM> without the first sub-layer <NUM> (not pictured). In such embodiments, the second sub-layer <NUM> may be directly atop one of the first major surface <NUM>, second major surface <NUM>, and/or side surface <NUM> of the body <NUM> and the third sub-layer <NUM> may be directly atop the second sub-layer upper surface <NUM> of the second sub-layer <NUM>. In such embodiments, the second sub-layer <NUM> acts as a sealant and is capable of sealing the one of the first major surface <NUM>, second major surface <NUM>, and/or side surface <NUM> of the body <NUM>, while simultaneously acting as an insulative barrier created from the glass-forming composition of the inorganic composition.

According to other embodiments, the coating <NUM> may comprise only the second sub-layer <NUM>. In such embodiments, the second sub-layer <NUM> acts as a sealant and is capable of sealing one of the first major surface <NUM>, second major surface <NUM>, and/or side surface <NUM> of the body <NUM>, while simultaneously acting as a insulative barrier created from the glass-forming composition of the inorganic composition, in situations where moisture resistance of the coating is not required.

Referring now to <FIG>, the body <NUM> may comprise a cellulosic layer <NUM>, whereby the coating <NUM> is applied directly to the cellulosic layer <NUM> of the body <NUM>. In other embodiments where the body <NUM> may be a laminate structure comprising multiple layers that includes a cellulosic layer <NUM> atop a substrate layer <NUM> with an adhesive layer <NUM> positioned there-between. The body <NUM> may also comprise the substrate layer <NUM> without the cellulosic layer <NUM> or adhesive layer <NUM>, whereby the coating <NUM> is applied to at least one surface of the substrate layer <NUM> - as discussed further herein.

Referring to <FIG>, the cellulosic layer <NUM> may comprise an upper cellulosic surface <NUM> and a lower cellulosic surface <NUM> opposite the upper cellulosic surface <NUM>. The cellulosic layer <NUM> may comprise a cellulosic side surface <NUM> that extends from the upper cellulosic surface <NUM> to the lower cellulosic surface <NUM> and forms a perimeter of the cellulosic layer <NUM>. The cellulosic side surface <NUM> may form a portion of the side surface <NUM> of the body <NUM>. Stated otherwise, the side surface <NUM> of the body <NUM> may comprise the cellulosic side surface <NUM>. The side surface <NUM> of the body <NUM> may form a major side surface <NUM> of the building panel <NUM>. The first major surface <NUM> of the body <NUM> may comprise the upper cellulosic surface <NUM>.

The cellulosic layer <NUM> may have a cellulosic layer thickness "tCL" as measured by the distance between the upper and lower cellulosic surfaces <NUM>, <NUM>. The cellulosic layer thickness tCL may range from about <NUM> (<NUM> mils) to about <NUM> (<NUM>,<NUM> mils) - including all values and sub-ranges there-between. In some embodiments, the cellulosic layer <NUM> may form a veneer that is bonded to the substrate layer <NUM> by the adhesive layer <NUM>, whereby the cellulosic thickness tCL may range from about <NUM> (<NUM> mils) to about <NUM> (<NUM> mils) - including all values and sub-ranges there-between. In other embodiments, the cellulosic layer <NUM> may form the entirety of the body <NUM>, whereby the cellulosic thickness tCL may range from about <NUM> (<NUM> mils) to about <NUM> (<NUM>,<NUM> mils) - including all values and sub-ranges there-between.

The cellulosic layer <NUM> may be formed from a cellulosic material such as wood, bamboo, and a combination thereof, and may be naturally occurring or engineered. Non-limiting examples of wood include cherry, maple, oak, walnut, pine, poplar, spruce, chestnut, mahogany, rosewood, teak, ash, hickory, beech, birch, cedar, fir, hemlock, basswood, alder wood, obeche wood, and combinations thereof. The cellulosic layer <NUM> may comprise pores that are not only present within the body of the cellulosic layer <NUM> but also exposed on at least one of the upper cellulosic surface <NUM>, lower cellulosic surface <NUM>, and/or the cellulosic side surface <NUM>. The porosity of the cellulosic layer <NUM> will depend on the bamboo or type of wood selected as the material that forms the cellulosic layer <NUM>.

The benefit of using a cellulosic layer <NUM> is that the resulting building panel <NUM> will exhibit authentic decorative features <NUM> of real wood and/or bamboo (e.g., wood grain, knots, burl, etc.) while minimizing the overall thickness required for the building panel <NUM> without necessitating artificial print layers. Artificial print layers, such as those on various papers or plastics, have been used as a way to recreate wood grain, knots, burl, etc., while minimizing layer thickness. Such print layers, however, are undesirable because of the limited amount of variation the cellulosic pattern across a large number of panels as compared to the same large number of panels that use cellulosic layers formed from real wood and/or bamboo. Stated otherwise, artificial print layers are not preferred because of the repetition in the decorative pattern over large installation areas.

Although not limited to this embodiment, the coating <NUM> may be directly atop the upper cellulosic surface <NUM>, the lower cellulosic surface <NUM>, and/or the cellulosic side surface <NUM> of the cellulosic layer <NUM>. The coating <NUM> may be applied to the cellulosic layer <NUM> such that the lower coating surface <NUM> is in direct contact with the upper cellulosic layer surface <NUM>. In such embodiments, the lower coating surface <NUM> may directly contact the upper cellulosic surface <NUM>, such that the upper coating surface <NUM> forms at least a portion of the upper major surface <NUM> of the building panel <NUM>.

Referring now to <FIG>, according to some embodiments of the present invention the building panel <NUM> may include cellulosic layer <NUM> being adhesively bonded to the substrate layer <NUM> by an adhesive layer <NUM>. The combination of layers <NUM>, <NUM>, <NUM>, <NUM> of the present invention creates a laminate structure having high lamination integrity in a ceiling system under both standard conditions (i.e. daily operation of an interior building environment) but also during exposure to the extreme heat and temperature that may result from a fire.

The substrate layer <NUM> may be formed from a metallic material, ceramic material, or composite material. Non-limiting examples of metallic material include aluminum, steel, and iron. In a preferred embodiment, the substrate layer <NUM> is formed from aluminum. The substrate layer <NUM> may have a substrate thickness "ts" ranging from about <NUM> (<NUM> mils) to about <NUM> (<NUM> mils) - including all values and sub-ranges there-between. The substrate thickness ts may range from about <NUM> (<NUM> mils) to about <NUM> (<NUM> mils). In a preferred embodiment, the substrate thickness ts ranges from about <NUM> (<NUM> mils) to about <NUM> (<NUM> mils) - including all values and sub-ranges there-between.

The adhesive layer <NUM> may comprises an upper adhesive surface <NUM> and a lower adhesive surface <NUM> opposite the upper adhesive surface <NUM>. The adhesive layer <NUM> may comprise an adhesive side surface <NUM> that extends from the upper adhesive surface <NUM> to the lower adhesive surface <NUM> and forms a perimeter of the adhesive layer <NUM>. The adhesive side surface <NUM> may form a portion of the side surface <NUM> of the body <NUM>. Stated otherwise, the side surface <NUM> of the body <NUM> may comprise the adhesive side surface <NUM>. The adhesive layer <NUM> may have an adhesive thickness "tA" ranging from about <NUM> (<NUM> mils) to about <NUM> (<NUM> mils) - including all values and sub-ranges there-between - as measured from the upper adhesive surface <NUM> to the lower adhesive surface <NUM>. In a preferred embodiment, the adhesive thickness tA ranges from about <NUM> (<NUM> mils) to about <NUM> (<NUM> mils) - including all values and sub-ranges there-between.

According to embodiments where the building panel <NUM> has the laminate structure, the overall panel thickness tP of the building panel <NUM> may be the summation of the substrate thickness ts, the adhesive thickness tA, the cellulosic layer thickness tCL, and the coating thickness tc as follows: <MAT>.

The upper substrate surface <NUM> of the substrate layer <NUM> may directly contact the lower adhesive surface <NUM> of the adhesive layer <NUM> and the upper adhesive surface <NUM> of the adhesive layer <NUM> may directly contact the lower cellulosic surface <NUM> of the cellulosic layer <NUM> such that the adhesive layer <NUM> adhesively bonds together the cellulosic layer <NUM> and the substrate layer <NUM>. The lower coating surface <NUM> may directly contact the upper cellulosic surface <NUM>, such that the upper coating surface <NUM> forms at least a portion of the upper major surface <NUM> of the building panel <NUM>. In such embodiments, the lower substrate surface <NUM> may form at least a portion of the lower major surface <NUM> of the building panel <NUM>.

The adhesive layer <NUM> may be formed from an adhesive composition that is a hot-melt composition, water-based polyvinyl acetate adhesive, and combinations thereof. According to the purposes of the present invention, the term "hot-melt adhesive composition" means a composition having a melt viscosity that ranges from about <NUM> Pa•s (<NUM>,<NUM> centipoise) to about <NUM> Pa•s (<NUM>,<NUM> centipoise) at a temperature of about <NUM> (<NUM> °F) - including all values and sub-ranges there-between. The hot-melt adhesive composition may be solid at room temperature and be substantially free of solvent. The adhesive composition may comprise adhesive polymer in an amount ranging from about <NUM> wt. % to about <NUM> wt. % based on the total weight of the adhesive composition - including all values and sub-ranges there-between.

The adhesive polymer according to the present invention may be a thermoplastic polymer. Non-limiting examples of the thermoplastic polymer may include moisture cured polyester modified polyurethane polymers. Such polyester modified polyurethanes may be formed by reacting organic diisocyanate with difunctional polyester polyol and low molecular weight diols (as chain-extending agents) at a non-limiting NCO:OH ratio of about <NUM>:<NUM> to about <NUM>:<NUM> - including all sub-ranges and ratios there-between.

Non-limiting examples of polyester polyol include di-functional polyester diols containing alcoholic hydroxyl groups. Suitable polyester diols are polyester having average molecular weights of from <NUM> to <NUM> and preferably from <NUM> to <NUM> produced from (i) dicarboxylic acids containing at least <NUM> carbon atoms, such as adipic acid, pimelic acid, suberic acid, azelaic acid and/or sebacic acid (preferably adipic acid, as the sole acid component) and (ii) alkane diols that may contain at least <NUM> carbon atoms, such as, for example, <NUM>,<NUM>-dihydroxy-butane, <NUM>,<NUM>-dihydroxypentane and/or <NUM>,<NUM>-dihydroxy-hexane. Polycondensates of ω-hydroxyalkane-mono-carboxylic acids and the polymers of their lactones are also suitable, although less preferred.

Low molecular weight diols suitable as chain-extending agents in accordance with the present invention include, in particular, aliphatic diols having average molecular weight of from <NUM> to <NUM> or mixtures thereof. Non-limiting examples of such diols include ethylene glycol, <NUM>,<NUM>-dihydroxy-propane, <NUM>,<NUM>-dihydroxy-butane, <NUM>,<NUM>-dihydroxypentane, <NUM>,<NUM>-dihydroxyhexane, and the like.

Non-limiting examples of suitable aromatic polyisocyanates include all isomers of toluylene-diisocyanate (TDI), naphthalene-<NUM>,<NUM>-diisocyanate, diphenylmethane-<NUM>,<NUM>'-diisocyanate (MDI), diphenylmethane-<NUM>,<NUM>'-diisocyanate and mixtures of <NUM>,<NUM>'-diphenylmethane-diisocyanate with the <NUM>,<NUM>' isomer or mixtures thereof with oligomers of higher functionality (so-called crude MDI), xylylene-diisocyanate (XDI), <NUM>,<NUM>'-diphenyl-dimethylmethane-diisocyanate, di- and tetraalkyl-diphenylmethane-diisocyanate, <NUM>,<NUM>'-dibenzyl-diisocyanate, <NUM>,<NUM>-phenylene-diisocyanate and <NUM>,<NUM>-phenylene-diisocyanate. Examples of suitable cycloaliphatic polyisocyanates are the hydrogenation products of the above-mentioned aromatic diisocyanates, such as <NUM>,<NUM>'-dicyclohexylmethane-diisocyanate (H<NUM>MDI), <NUM>-isocyanatomethyl-<NUM>-isocyanato-<NUM>,<NUM>,<NUM>-trimethylcyclohexane (isophorone-diisocyanate, IPDI), cyclohexane-<NUM>,<NUM>-diisocyanate, hydrogenated xylylene-diisocyanate (H<NUM>XDI), <NUM>-methyl-<NUM>,<NUM>-diisocyanato-cyclohexane, m- or p-tetramethylxylene-diisocyanate (m-TMXDI, p-TMXDI) and dimer-fatty acid diisocyanate. Examples of aliphatic polyisocyanates are tetramethoxybutane-<NUM>,<NUM>-diisocyanate, butane-<NUM>,<NUM>-diisocyanate, hexane-<NUM>,<NUM>-diisocyanate (HDI), <NUM>,<NUM>-diisocyanato-<NUM>,<NUM>,<NUM>-trimethylhexane, <NUM>,<NUM>-diisocyanato-<NUM>,<NUM>,<NUM>-trimethylhexane and <NUM>,<NUM>-dodecane-diisocyanate (C<NUM>DI).

The adhesive composition of the present invention may further comprise additives selected from the group consisting of <NUM>,<NUM>'-dimorpholinethyl ether catalyst, di(<NUM>,<NUM>-dimethylmorpholinoethyl)ether catalyst, adhesion promoters, diluents, plasticizers, fillers, antioxidants pigments, UV absorbers and combinations thereof. In other embodiments, the adhesive composition may further comprise a flame retardant. Non-limiting examples of flame retardant may include ammonium hydroxide, magnesium hydroxide, huntite, hydromagnesite, silica, polyphosphate, melamine cyanurate, chloride salts - such as sodium chloride, antimony oxide, and borates, such as calcium borate, magnesium borate, zinc borate, and combinations thereof. The flame retardant may be present in the adhesive composition in an amount ranging from about <NUM> wt. % to about <NUM> wt. % based on the total weight of the adhesive composition - including all values and sub-ranged there-between.

The building panel <NUM> of <FIG> may be formed heating the adhesive composition to an application temperature ranging from about <NUM>,<NUM> (<NUM> °F) to about <NUM>,<NUM> (<NUM> °F), and applying the adhesive composition to at least one of the upper substrate surface <NUM> or the lower cellulosic surface <NUM>. The adhesive composition may be applied by roll coating, spray coating, dip coating, or the like. Within the open time of the adhesive (typically <NUM> to <NUM> seconds), the upper substrate surface <NUM> is mated to the lower cellulosic surface <NUM> with the adhesive composition being present there-between, thereby bonding the upper substrate surface <NUM> to the lower cellulosic surface <NUM> via the adhesive composition. Pressure may then be applied to at least one of the upper cellulosic surface <NUM> of the cellulosic layer <NUM> or the lower substrate surface <NUM> of the substrate layer <NUM> to ensure proper adhesive bonding.

Each sub-layer <NUM>, <NUM>, <NUM> may be individually applied by spray, roll-coating, dip coating, curtain coating, brushing, blade coating, or the like. Specifically, the first sub-layer <NUM> may be applied to the upper cellulosic surface <NUM> of the cellulosic layer <NUM>. The first sub-layer <NUM> may then be optionally heated to a temperature ranging from about <NUM> (<NUM> °F) to about <NUM> (<NUM> °F) to partially or fully cure the first sub-layer <NUM>. The second sub-layer <NUM> may then be applied to the first sub-layer supper surface upper surface <NUM>. The second sub-layer <NUM> may then be optionally heated to a temperature ranging from about <NUM> (<NUM> °F) to about <NUM>,<NUM> (<NUM> °F) to partially or fully cure the second sub-layer <NUM>. The third sub-layer <NUM> may then be applied to the second sub-layer upper surface <NUM>. The third sub-layer <NUM> may then be optionally heated to a temperature ranging from about <NUM> (<NUM> °F) to about <NUM> (<NUM> °F) to partially or fully cure the third sub-layer <NUM> - thereby resulting in the laminate structure of the present invention. The laminate structure may then be heated in an oven to fully cure the adhesive layer <NUM> and the coating <NUM> for a fourth period of time.

According to the present invention, the coating <NUM> applied to the cellulosic layer <NUM> provides an aesthetically pleasing building panel <NUM> such that the underlying body decorative features on the body <NUM> are visible from the upper major surface <NUM> of the building panel <NUM> as the decorative features <NUM>, because the decorative coating <NUM> is substantially clear. Furthermore, the inorganic composition of the coating <NUM> helps provide an insulative heat-barrier to the cellulosic layer <NUM>, thereby helping prevent the cellulosic layer <NUM> from igniting during a fire and propagating through the building panel <NUM>.

The multi-layered coating <NUM> comprising the first sub-layer <NUM> may also at least partially seal the pores and the upper cellulosic surface <NUM> such that at least a portion of the glass layer is formed at a distance separated from the upper cellulosic surface <NUM> of the cellulosic layer <NUM> - further protecting the cellulosic layer <NUM> from igniting in a fire. Additionally, the moisture sealant composition of the third sub-layer <NUM> ensures that the glass-forming composition of the underlying sub-layers <NUM>, <NUM> remains active for prolonged periods of time in case an interior space catches fire years after initial installation.

Referring to <FIG>, the building panel <NUM> of the present invention may be a ceiling panel (as shown installed in the ceiling system of <FIG>), a wall panel, or the like. The lower major surface <NUM> of the ceiling panel <NUM> of the present invention may face the plenum space <NUM> of an interior space of a ceiling system <NUM>. The upper major surface <NUM> of the ceiling panel <NUM> of the present invention may face the active space <NUM> of an interior space of a ceiling system <NUM>.

In non-exemplified embodiments, the present invention may include a building panel having an upper major surface opposite a lower major surface, the building panel comprising a cellulosic layer (also referred to as "cellulosic body" in this embodiment) and a coating. The cellulosic body is self-supporting and comprises an upper cellulosic surface and a lower cellulosic surface opposite the upper cellulosic body. Non-limiting examples of a cellulosic body may include MDF board, wooden planks, or the like. The cellulosic body may have a cellulosic body thickness as measured from the lower cellulosic surface to the upper cellulosic surface that ranges up to about <NUM> (<NUM> inches) - including all values and sub-ranges there-between.

With the coating <NUM> being formed at drying temperatures as low as <NUM> (<NUM> °F), the cellulosic body may at least partially retain pre-existing moisture already contained within the cellulosic body. The surprising benefit of retaining the pre-existing moisture is that during exposure to high-heat, the retained moisture is converted to steam and driven out of the cellulosic body. As the steam escapes from the body <NUM>, the glass layer formed from the coating <NUM> is pushed outward from the body <NUM>, thereby increasing the distance between the body <NUM> and the surrounding flame or high-heat - thereby decreasing the likelihood that the body <NUM> ignites. Stated otherwise, it has been surprisingly discovered that the coatings <NUM> of the present invention further enhance fire repellency in the building panels <NUM> by allowing for drying temperatures below <NUM> (<NUM> °F) under atmospheric conditions (at <NUM>, <NUM> kPa (<NUM> atm)).

The building panel <NUM> of such embodiments may have the coating <NUM> applied to at least one of the upper cellulosic surface <NUM> or the lower cellulosic surface <NUM> of the cellulosic body <NUM>. The coating <NUM> comprises an upper coating surface <NUM> opposite a lower coating surface <NUM>, whereby the lower coating surface <NUM> of the coating <NUM> may directly contact the upper cellulosic surface <NUM> of the cellulosic body <NUM>. The coating <NUM> comprises at least the second sub-layer <NUM> and optionally the first sub-layer <NUM> and/or the third sub-layer <NUM>, as previously discussed. The upper major surface <NUM> of the building panel <NUM> may comprise the upper coating surface <NUM> of the coating <NUM>. According to some embodiments, the lower major surface <NUM> of the building panel <NUM> may be uncoated, whereby the lower major surface <NUM> of the building panel <NUM> does not comprise the coating <NUM>, but rather the lower cellulosic surface <NUM> or the lower substrate surface <NUM>.

Referring now to <FIG>, a building panel <NUM> and ceiling system <NUM> are illustrated in accordance with another embodiment of the present invention. The building panel <NUM> is similar to the building panel <NUM> except as described herein below. The description of the building panel <NUM> above generally applies to the building panel <NUM> described below except with regard to the differences specifically noted below. A similar numbering scheme will be used for the building panel <NUM> as with the building panel <NUM> except that the <NUM>-series of numbers will be used. Additionally, the ceiling system <NUM> is similar to the ceiling system <NUM> except as described herein below. The description of the ceiling system <NUM> above generally applies to the ceiling system <NUM> described below except with regard to the differences specifically noted below. A similar numbering scheme will be used for the ceiling system <NUM> as with the ceiling system <NUM> except that the <NUM>-series of numbers will be used.

The coating <NUM> of the present invention may be applied to one of the first major surface <NUM>, second major surface <NUM>, and/or side surface <NUM> of the body <NUM>. In a preferred embodiment, the coating <NUM> is applied to each of the first major surface <NUM>, the second major surface <NUM>, and the side surface <NUM> of the body <NUM> such that the coating <NUM> encapsulates the body <NUM>. Stated otherwise, the coating <NUM> may form a continuous barrier that substantially surrounds the entire body <NUM>.

Although not pictured, the coating <NUM> of this embodiment comprises the second sub-layer <NUM>, and may further comprise each of the first sub-layer <NUM> and/or third sub-layer <NUM>, as previously discussed with respect to <FIG>.

In these embodiments, the body <NUM> may formed entirely from the cellulosic body <NUM> or the substrate layer <NUM>. The body <NUM> may alternatively be formed from the laminate structure. According to the embodiments where the body <NUM> is formed entirely from the cellulosic body <NUM>, the overall panel thickness tP may be the summation of cellulosic body thickness tCL, and the coating thickness tc as follows: <MAT>.

whereby the "n" refers to the number of major surfaces of the body <NUM> coated with the coating <NUM>. In this embodiment, the first and second major surfaces <NUM>, <NUM> of the body <NUM> are coated and n = <NUM>. In such embodiments, the panel thickness tP may range from about <NUM> (<NUM> mils) to about <NUM> (<NUM>,<NUM> mils) - including all values and sub-ranges there-between.

According to the embodiments where the body <NUM> is formed entirely from the substrate layer <NUM>, the overall panel thickness tP may be the summation of substrate layer thickness tS, and the coating thickness tc as follows: <MAT>.

whereby the "n" refers to the number of major surfaces of the body <NUM> coated with the coating <NUM>. In this embodiment, the first and second major surfaces <NUM>, <NUM> of the body <NUM> are coated and n = <NUM>. In such embodiments, the panel thickness tP may range from about <NUM>,<NUM> (<NUM> mils) to about <NUM>,<NUM> (<NUM> mils) - including all values and sub-ranges there-between.

Referring now to <FIG>, the building panel <NUM> of these embodiments may be installed into a ceiling system <NUM> comprising a support <NUM> that includes a first support member 1005a and a second support member 1005b. The first and second support members 1005a, 1005b may be arranged in an intersecting pattern to form a support grid. A plurality of the building panels <NUM> may be arranged in an array and attached to the support grid such that the upper major surface of one building panel <NUM> faces the lower major surface of a second building panel <NUM> that is adjacent to the first building panel <NUM>. The plurality of the building panels <NUM> may also be arranged and attached to the support grid such that the plurality of building panels <NUM> comprises a first side <NUM> opposite a second side <NUM>, whereby the firs side <NUM> faces the plenum <NUM> and the second side <NUM> faces the room environment <NUM> - the first and second sides <NUM>, <NUM> comprises the side surface <NUM> of the building panels <NUM>.

The following examples are prepared in accordance_with the present invention. The present invention is not limited to the examples described herein, but just by the appended claims.

A first experiment was performed by coating a major surface of a first cellulosic body with a wet-state inorganic composition containing the metal-complexing agent of the present invention (i.e., Example <NUM>). A second cellulosic body was then coated with a comparative coating (i.e., Comparative Example <NUM>) that did not contain the metal complexing agent. Each coated body was then dried at a temperature of about <NUM> (<NUM> °F) for a period of <NUM> minutes, followed by each coated body being cured at a temperature of about <NUM> (<NUM> °F) for a period of <NUM> minutes. The formulation of Example <NUM> and Comparative Example <NUM> are set forth below in Table <NUM>.

The dispersing agent is a non-ionic dispersing agent. The complexing agent is an iron-containing complexing agent, whereby iron is present in an amount of <NUM> wt. % based on the total weight of the complexing agent. Each specimen was then evaluated for cracking, blistering, and heat-damage to the underlying cellulosic body. The results are set forth below in Table <NUM>.

As demonstrated by Table <NUM>, the addition of the metal complexing agent in Example <NUM> resulted in a coating having a uniform absence of blistering and cracking. Thus, even at cure temperatures as low as <NUM> (<NUM> °F), the presence of the metal complexing agent results in a thorough and uniform cure throughout the coating. In comparison, the absence of the metal-complexing agent in Comparative Example <NUM> resulted in a coating having blistering and cracking - indicating improper cross-link throughout the coating at a temperature of <NUM> (<NUM> °F). Furthermore, by curing at temperatures as low as <NUM> (<NUM> °F), the cellulosic bodies underwent little-to-no heat damage. Thus, it has been discovered that not only does the presence of the metal complexing agent lower the temperature needed to impart complete and uniform cross-linking within the coating composition, but it also prevents the underlying cellulosic substrate from being damaged during processing by avoiding excessive curing temperatures that would otherwise be needed to properly cure the coating composition.

A second experiment was performed by coating a major surface of a number of cellulosic bodies with the inorganic composition of the present invention in the wet-state. This experiment used the same metal complexing agent as used in Experiment <NUM>. Each coated body was then dried at a temperature of about <NUM> (<NUM> °F) for a period of <NUM> minutes, followed by each coated body being cured at a temperature of about <NUM> (<NUM> °F) for a period of <NUM> minutes. The formulations are set forth below in Table <NUM>.

Each specimen was then evaluated for adhesion, hardness, coating discoloration, and heat-damage to the underlying cellulosic body. The results are set forth below in Table <NUM>.

Claim 1:
A flame-retardant coating composition comprising:
a liquid carrier;
a flame-retardant blend comprising a phosphate compound and a metal complexing agent; and
characterized in that the phosphate compound and the metal complexing agent are present in a weight ratio ranging from about <NUM>:<NUM> to about <NUM>:<NUM> and
in that the liquid carrier is water, and wherein the metal complexing agent comprises a metal ion and one or more phosphate, arsenate, or organic ligands.