Patent Description:
Ceiling systems are installed into room environments to help control noise as well as enhance the aesthetic appeal of those room environments. These ceiling systems may comprise one or more building panels having specific aesthetic properties that help contribute to the appeal of the room environment. Previous attempts at improving the aesthetic properties of these building panels included applying decorative coatings to the surface of the building panel. However, such decorative coatings tend to create difficulties associated with manufacturing time as well as the overall performance of the building panel at high-temperatures (i.e., increased flammability and/or blistering of the coating). Thus there exists a need for building panels comprising a decorative coating applied thereto that does not create the same difficulties with respect to manufacturing and while also not sacrificing the required aesthetic properties provided by the decorative coating.

The present invention is directed to a coated building panel according to claim <NUM>.

In other embodiments, the present invention is directed to a method according to claim <NUM>.

In other embodiments, the present invention is directed to a coated building panel comprising: a body comprising an upper surface opposite a lower surface and a side surface extending between the upper surface and the lower surface; a surface coating atop the upper surface, the surface coating comprising: about <NUM> wt. % to about <NUM> wt. % of a pigment based on the total weight of the surface coating, the pigment comprising an inorganic pigment having a particle size ranging from <NUM> to <NUM>; and a polymeric dispersant comprising a polymer backbone and pendant side chains extending from the polymer backbone; wherein the surface coating comprises less than <NUM> wt. % of a liquid carrier based on the total weight of the surface coating.

Other embodiments of the present invention include a method of forming a building panel having an edge coating, the method comprising: a) providing a body having an upper surface opposite a lower surface and a side surface extending between the upper surface and the lower surface; b) applying a thixotropic coating composition to the side surface, the thixotropic coating composition comprising a liquid carrier, a pigment, a dispersant, and a binder having a glass transition temperature less than about <NUM>; and c) drying the thixotropic coating composition for a drying period to form the edge coating, the edge coating having less than about <NUM> wt. % of the liquid carrier; wherein the thixotropic coating composition has a solid's content ranging from about <NUM> wt. % to about <NUM> wt. % based on the total weight of the thixotropic coating composition.

Other embodiments of the present invention provide a coated building panel comprising: a body comprising an upper surface opposite a lower surface and a side surface extending between the upper surface and the lower surface; a thixotropic surface coating applied to the side surface, the surface coating comprising: a binder having a glass transition temperature less than about <NUM>; and pigment in an amount ranging from about <NUM> wt. % to about <NUM> wt. % based on the total weight of the surface coating, the pigment comprising inorganic pigments; a ionic dispersant; wherein the surface coating is present in an amount ranging from about <NUM>/m<NUM> to about <NUM>/m<NUM>.

Other embodiments of the present invention include a coating composition comprising a liquid carrier, an inorganic pigment; and an ionic polymeric dispersant comprising a polymer backbone and pendant side chains extending from the polymer backbone, wherein the coating composition has a solid's content ranging from about <NUM> wt. % to about <NUM> wt. % based on the total weight of the coating composition.

(For Chemical Cases) Unless otherwise specified, all percentages and amounts expressed herein and elsewhere in the specification should be understood to refer to percentages by weight.

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

Referring to <FIG> and <FIG>, the present invention includes a coated building panel <NUM> (referred to herein as "building panel") comprising a first major surface <NUM> opposite a second major surface <NUM> and a side surface <NUM> that extends between the first major surface <NUM> and the second major surface <NUM>, thereby defining a perimeter of the ceiling panel <NUM>. The side surface <NUM> may comprise an upper portion 113a and a lower portion 113b, wherein the upper portion 113a is adjacent to the first major surface <NUM> and the lower portion 113b is adjacent to the second major surface <NUM>.

Referring to <FIG>, the present invention may further include a ceiling system <NUM> comprising 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> provides space for mechanical lines within a building (e.g., HVAC, plumbing, etc.). 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.).

In the installed state, the building panels <NUM> may be supported in the interior space by one or more parallel support struts <NUM>. Each of the support struts <NUM> may comprise an inverted T-bar having a horizontal flange <NUM> and a vertical web <NUM>. The ceiling system <NUM> may further comprise a plurality of first struts that are substantially parallel to each other and a plurality of second struts that are substantially perpendicular to the first struts (not pictured). In some embodiments, the plurality of second struts intersects the plurality of first struts to create an intersecting ceiling support grid <NUM>. The plenum space <NUM> exists above the ceiling support grid <NUM> and the active room environment <NUM> exists below the ceiling support grid <NUM>.

In the installed state, the first major surface <NUM> of the building panel <NUM> may face the active room environment <NUM> and the second major surface <NUM> of the building panel <NUM> may face the plenum space <NUM>. The building panel <NUM> may be installed according to at least two variations. In a first variation, the building panel <NUM> is positioned entirely above the horizontal flange <NUM> of the support struts <NUM>. In the first variation, at least a portion of the first major surface may be concealed from the active room environment <NUM> by the horizontal flange <NUM> because the horizontal flange <NUM> contacts the first major surface <NUM>, thereby supporting it in the ceiling system <NUM>. In the first variation, the entire side surface <NUM> - including the upper portion 113a and the lower portion 113b - may be concealed from the active room environment <NUM> by the horizontal flange <NUM>. The second variation will be described further herein.

Referring now to <FIG> and <FIG>, the building panel <NUM> of the present invention may have a panel thickness t<NUM> as measured from the first major surface <NUM> to the second major surface <NUM>. The panel thickness t<NUM> may range from about <NUM> to about <NUM> - including all values and sub-ranges there-between. The building panel <NUM> may have a length LP ranging from about <NUM> to about <NUM> - including all values and sub-ranges there-between. The building panel <NUM> may have a width WP ranging from about <NUM> to about <NUM> - including all values and sub-ranges there-between.

The building panel <NUM> may comprise a body <NUM> and a surface coating <NUM> applied thereto - as discussed further herein. The body <NUM> comprises an upper surface <NUM> opposite a lower surface <NUM> and a body side surface <NUM> that extends between the upper surface <NUM> and the lower surface <NUM>, thereby defining a perimeter of the body <NUM>. The body <NUM> may have a body thickness t<NUM> that extends from the upper surface <NUM> to the lower surface <NUM>. The body thickness t<NUM> may range from about <NUM> to about <NUM> - including all values and sub-ranges there-between.

The body <NUM> may be porous, thereby allowing airflow through the body <NUM> between the upper surface <NUM> and the lower surface <NUM> - as discussed further herein. The body <NUM> may be comprised of a binder and fibers. In some embodiments, the body <NUM> may further comprise a filler and/or additive.

Non-limiting examples of binder may include a starch-based polymer, polyvinyl alcohol (PVOH), a latex, polysaccharide polymers, cellulosic polymers, protein solution polymers, an acrylic polymer, polymaleic anhydride, epoxy resins, or a combination of two or more thereof. Non-limiting examples of filler may include powders of calcium carbonate, limestone, titanium dioxide, sand, barium sulfate, clay, mica, dolomite, silica, talc, perlite, polymers, gypsum, wollastonite, expanded-perlite, calcite, aluminum trihydrate, pigments, zinc oxide, or zinc sulfate.

The fibers may be organic fibers, inorganic fibers, or a blend thereof. Non-limiting examples of inorganic fibers mineral wool (also referred to as slag wool), rock wool, stone wool, and glass fibers. Non-limiting examples of organic fiber include fiberglass, cellulosic fibers (e.g. paper fiber - such as newspaper, hemp fiber, jute fiber, flax fiber, wood fiber, or other natural fibers), polymer fibers (including polyester, polyethylene, aramid - i.e., aromatic polyamide, and/or polypropylene), protein fibers (e.g., sheep wool), and combinations thereof.

Referring now to <FIG>, the building panel <NUM> may further comprise the surface coating <NUM> applied to at least one of the first major surface <NUM> and/or the side surface <NUM> of the body <NUM>. The surface coating <NUM> may be a color surface coating <NUM>. According to the present invention the terms "color surface coating" and "surface coating" may be used interchangeably. The term "color surface coating" <NUM> refers to a surface coating <NUM> comprising a color pigment and the resulting surface coating <NUM> exhibits a color on the visible color spectrum - i.e., violet, blue, green, yellow, orange, or red. The color surface coating <NUM> may also have a color of white, black, or grey. The color surface coating <NUM> may further comprise combinations of two or more colors - such a primary color (i.e., red, yellow, blue) as well as an achromatic color (i.e., white, grey).

A non-limiting example of a color surface coating <NUM> may be pink and produced from a combination of red and white pigments. Another non-limiting example of a color surface coating <NUM> may be green and produced from a combination of blue and yellow pigments. Another non-limiting example of a color surface coating <NUM> may be brown and produced from a combination of red, yellow, and black pigments.

In some embodiments, the surface coating <NUM> may include a face coating <NUM> that is applied to the first major surface <NUM> of the body <NUM>. In other embodiments, the surface coating <NUM> may include an edge coating <NUM> that is applied to the side surface <NUM> of the body <NUM>. In other embodiments, the building panel <NUM> may comprise both the face coating <NUM> applied to the first major surface <NUM> of the body <NUM> as well as the edge coating <NUM> applied to the side surface <NUM> of the body <NUM>.

The face coating <NUM> may comprise an upper surface <NUM> opposite a lower surface <NUM>. The face coating <NUM> has a face coating thickness t<NUM> - as measured from the upper surface <NUM> to the lower surface <NUM> of the face coating <NUM>. The face coating thickness t<NUM> may range from about <NUM> (micron) to about <NUM> - including all thicknesses and sub-ranges there-between. The lower surface <NUM> of the face coating <NUM> may be in direct contact with the upper surface <NUM> of the body <NUM>. The upper surface <NUM> of the face coating <NUM> may form at least a portion of the first major surface <NUM> of the building panel <NUM> - as discussed further herein.

Although not shown, the building panel <NUM> of the present invention may further comprise a non-woven scrim. The non-woven scrim may comprise an upper surface opposite a lower surface. The lower surface of the non-woven scrim may be positioned immediately adjacent to and in direct contact with the upper surface <NUM> of the body <NUM>. The face coating <NUM> may be applied to the non-woven scrim such that the lower surface <NUM> of the face coating <NUM> is in direct contact with the upper surface of the non-woven scrim.

The face coating <NUM> may comprise a first binder, a first pigment, and a first dispersant. The face coating <NUM>, in the dry-state, may be present on the upper surface <NUM> of the body <NUM> in an amount ranging from about <NUM>/m<NUM> to about <NUM>/m<NUM> - including all amounts and sub-ranges there-between. According to the present invention, the phrase "dry-state" indicates a composition that is substantially free of a liquid carrier (e.g., liquid water). Thus, the face coating <NUM> in the dry-state may comprise the first pigment, the first dispersant, the first binder, and less than about <NUM> wt. % of liquid carrier based on the total weight of the face coating <NUM>. In a preferred embodiment, the fact coating <NUM> in the dry-state has a solid's content of about <NUM> wt. % based on the total weight of the face coating <NUM>. Conversely, a composition that is in a "wet-state," which refers to a composition containing various amounts of liquid carrier - as discussed further herein.

The first binder may be present in the face coating <NUM> in an amount ranging from about <NUM> wt. % to about <NUM> wt. % based on the total dry-weight of the face coating <NUM> - including all wt. % and sub-ranges there-between. The first binder may be polymeric. The first binder may have a glass transition temperature ("Tg") that is greater than room temperature ("Tm") - wherein room temperature ranges from about <NUM> to about <NUM> - including all temperatures and sub-ranges there-between. In some embodiments, the first binder may have an overall charge that is anionic.

Non-limiting examples of the first binder include polymers selected from polyvinyl alcohol (PVOH), latex, an acrylic polymer, polymaleic anhydride, or a combination of two or more thereof. Non-limiting examples of latex binder may include a homopolymer or copolymer formed from the following monomers: vinyl acetate (i.e., polyvinyl acetate), vinyl propinoate, vinyl butyrate, ethylene, vinyl chloride, vinylidene chloride, vinyl fluoride, vinylidene fluoride, ethyl acrylate, methyl acrylate, propyl acrylate, butyl acrylate, ethyl methacrylate, methyl methacrylate, butyl methacrylate, hydroxyethyl methacrylate, hydroxyethyl acrylate, styrene, butadiene, urethane, epoxy, melamine, and an ester. Preferably the binder is selected from the group consisting of aqueous lattices of polyvinyl acetate, polyvinyl acrylic, polyurethane, polyurethane acrylic, polystyrene acrylic, epoxy, polyethylene vinyl chloride, polyvinylidene chloride, and polyvinyl chloride.

The first dispersant may be present in the face coating <NUM> in an amount ranging from about <NUM> wt. % to about <NUM> wt. % based on the total dry-weight of the face coating <NUM> - including all wt. % and sub-ranges there-between. The first dispersant may be ionic in nature - i.e., comprise one or more ionic groups such as anionic group or cationic group. In a preferred embodiment, the ionic group is anionic. The first dispersant may be polymeric having a molecular weight of at least <NUM>,<NUM> Mn. The first dispersant may comprise a hydrophilic portion and a hydrophobic portion - wherein the hydrophobic portion is used to attract to the first pigment while the first hydrophilic portion is used to disperse the attached pigment into the liquid carrier - i.e., water.

Referring now to <FIG>, the present invention may comprise the first pigment <NUM> treated with the first dispersant <NUM>, thereby forming a first dispersible pigment <NUM>. As demonstrated by <FIG>, the first dispersant <NUM> comprises a polymer backbone <NUM> and at least one pendant side-chain <NUM> that extends from the polymer backbone <NUM>. The ionic group <NUM> of the first dispersant <NUM> may be located at the tip of the pendant side-chain <NUM>. In a preferred embodiment, the first dispersant <NUM> comprises multiple pendant side-chains <NUM> - each of which have an ionic group <NUM> located at the tip of the pendant side-chain <NUM>.

The ionic group <NUM> is distanced from the polymer backbone <NUM> by a side-chain length as measured from the polymer backbone <NUM> to the tip or end of the pendant side-chain <NUM>. The separation of the ionic group <NUM> from the polymer backbone <NUM> via the pendant side-chain <NUM> allows for a greater number of ionic groups <NUM> to be attached to a single dispersant (i.e., the first dispersant <NUM>) because the ionic groups <NUM> are not forced apart by the steric hindrance of the polymer backbone <NUM> that normally results when ionic groups are located directly on the backbone of the polymer dispersant (for example, see <FIG> as discussed further herein). Less separation between ionic groups <NUM> on the first dispersant <NUM> results in a greater number of attachment points of the first dispersant <NUM> to the pigment <NUM>, thereby provides a stronger attachment of the first dispersant <NUM> to the first pigment <NUM>, thereby ensuring that the pigment is provided with the desired hydrophilicity imparted by the hydrophilic portion of the first dispersant <NUM>.

Additionally, less separation of ionic groups <NUM> on the first dispersant <NUM> allows for better attachment of the first dispersant <NUM> to pigments having a smaller particle size - i.e., pigments having a particle size less than about <NUM>. preferably less than about <NUM>. The first pigment having smaller particles may have a particle size ranging from about <NUM> (nanometer) to about <NUM> (including all sizes and sub-ranges there-between) - because the greater density of ionic groups <NUM> on the first dispersant <NUM> can better accommodate the smaller volume occupied by each of the first pigments that would other not be possible with pigments having ionic groups attached directly to the polymer backbone of a dispersant because of the steric hindrance of the polymer backbone.

According to some embodiments, the dispersant may comprise an anionic polyacrylic polymer having a salt group formed from a neutralization of an acid group with a compound forming a cation. For examples, the polymer may comprise one or more pendant side chains comprising a terminal carboxylic acid group that is neutralized with sodium or ammonia to form a carboxylate anion and a sodium cation and/or ammonium cation. Alternatively, the polymer may comprise one or more pendant side chains comprising a terminal sulfonic acid group that is neutralized with the aforementioned sodium or ammonia compounds to form a salt group.

The first dispersant of the present invention may have a pH ranging from about <NUM> to about <NUM> - including all pHs and sub-ranges there-between. In a preferred embodiment, the dispersant is an anionic polymer having a pH ranging from about <NUM> to about <NUM> - including all pHs and sub-ranges there-between. The first dispersant may have a specific gravity (relative to water) that is less than <NUM>. Specifically, the first dispersant may have a specific gravity (relative to water) ranging from about <NUM> to about <NUM> - including all specific gravities and sub-ranges there-between. In a preferred embodiment, the first dispersant may have a specific gravity (relative to water) of about <NUM>. The first dispersant may be commercially available as Zephrym™ PD <NUM>.

The first pigment may be present in the face coating <NUM> in an amount ranging from about <NUM> wt. % to about <NUM> wt. % - including all wt. % and sub-ranges there-between - based on the total dry-weight of the face coating <NUM>. Similar to the phrase "dry-state" - the phrase "dry-weight" refers to the weight of a component or composition without including any additional weight of liquid carrier. Thus, when calculating the dry weight of a component or composition, the calculation should be based solely on the weight of the solid components (e.g., dispersant, pigment, binder, etc.), and should exclude any amount of residual liquid carrier that may still be present from the wet-state.

The first pigment may be an inorganic pigment. The first pigment may be a particle exhibiting one of the previously discussed colors with respect to the color surface coating <NUM>. Thus, the face coating <NUM> may also be referred to herein as a "color face coating" <NUM>. Non-limiting examples of inorganic pigment include particles of carbon black, graphite, graphene, copper oxide, iron oxide, zinc oxide, calcium carbonate, manganese oxide, titanium dioxide and combinations thereof. The inorganic pigments may include individual particles having colors selected from, but not limited to, red, blue, yellow, black, green, brown, violet, white, grey and combinations thereof. The particles that make up the first pigment may have a particle size ranging from about <NUM> to about <NUM> - including all sizes and sub-ranges there-between.

Previously, using such pigments to create face coatings required the face coatings to be applied using large amounts of carrier (i.e., low solids content during application of the coatings) and/or large amounts of other additives because such pigments will easily aggregate, thereby forming clumps that result in undesirable aesthetic properties in the resulting face coating. According to the present invention, however, face coatings using such pigments may be formed using high-solid's contents without risk of aggregating - as described further herein.

Creating the face coating <NUM> on the building panel <NUM> that exhibits the desired aesthetic qualities - i.e., a superior colored face on the building panel <NUM> - is achieved by homogeneous distribution of the pigment within the face coating <NUM>. When using the first pigment, which has a maximum particle size of about <NUM>,<NUM>, ensuring proper distribution of the pigment may be obtained by adding the first dispersant to the face coating <NUM>. The dispersant may be polymeric and have an ionic charge.

According to some embodiments of the present invention, the first pigment may comprise carbon black, which exhibits a cationic charge, and the first dispersant may comprise anionic polyacrylic dispersant having a pH of about <NUM>.

The face coating <NUM> may be formed by applying a face coating composition in the wet-state. The face coating composition may comprise the first pigment, the first dispersant, and the first binder, as well as a liquid carrier. The liquid carrier may be selected from water, VOC solvent - such as acetone, toluene, methyl acetate - or combinations thereof. In a preferred embodiment, the liquid carrier is water and comprises less than <NUM> wt. % of VOC solvent based on the total weight of the liquid carrier.

The face coating composition has a high-solid's content. According to the present invention, the term "high solids content" refers to a solids content of at least <NUM> wt. % based on the total weight of the face coating composition. Stated otherwise, the liquid carrier is present in a maximum amount of about <NUM> wt. % based on the total weight of the face coating composition.

In a preferred embodiment, the solids content of the face coating composition range from about <NUM> wt. % to about <NUM> wt. % based on the total weight of the face coating composition - including all wt. % and sub-ranges there-between. In some embodiments, the face coating composition may have a solids content of at least <NUM> wt. % based on the total weight of the face coating composition. In some embodiments, the face coating composition may have a solids content of at least <NUM> wt. % based on the total weight of the face coating composition.

The solid's content is calculated as the fraction of materials present in the face coating composition that are not the liquid carrier. Specifically, the solid's content of the face coating composition may be calculated as the amount of dispersant, pigment, and binder in the face coating composition and dividing it by the total weight of the face coating composition (including liquid carrier).

Therefore, the amount of each component in the face coating composition may be calculated by multiplying the desired amount of each of the first dispersant, the first pigment, and the first binder present in the face coating <NUM> in the dry-state by the total solids content of the face coating composition. For example, for a face coating <NUM> in the dry-state comprising about <NUM> wt. % of pigment, whereby that face coating <NUM> is formed from a face coating composition having a solids content of <NUM> wt. % - the amount of the first pigment in the face coating composition would be <NUM> wt. % based on the total weight of the face coating composition in the wet-state - i.e., <NUM> wt. % x <NUM> = <NUM> wt. % of pigment in the face coating composition.

The face coating composition may have a viscosity ranging from about <NUM> cps to about <NUM>,<NUM> cps as measured by a Brookfield viscometer at <NUM> RPM using a #<NUM> spindle at room temperature - including all viscosities and sub-ranges there-between. In a preferred embodiment, the face coating composition may have a viscosity ranging from about <NUM> cps to about <NUM>,<NUM> cps as measured by a Brookfield viscometer at <NUM> RPM using a #<NUM> spindle at room temperature - including all viscosities and sub-ranges there-between. The face coating composition may have a viscosity ranging from about <NUM> cps to about <NUM> cps as measured by a Brookfield viscometer at <NUM> RPM using a #<NUM> spindle at room temperature - including all viscosities and sub-ranges there-between. The face coating composition may exhibit a cationic charge.

The face coating composition (i.e., in the wet-state) may be applied to the upper surface <NUM> of the body <NUM> in an amount ranging from about <NUM>/m<NUM> to about <NUM>/m<NUM> - including all sub-ranges and values there-between. The face coating composition may be applied to the upper surface <NUM> by roll coating, brush coating, and spray coating, and/or curtain blade.

Adding the first dispersant to the first coating composition of the present invention allows for not only the first pigment to have a maximum particle size of about <NUM>, but also allows for the first coating composition to have the aforementioned high solid's content without risk of causing the first pigment to aggregate. The high solid's content provides for faster application and drying of face coating composition into the face coating <NUM>. Specifically, after application to the body <NUM>, the face coating composition is dried, thereby driving off the liquid carrier thereby creating the face coating <NUM>, which as previously discussed is in the dry-state.

Specifically, the face liquid-based coating composition may be dried in a conventional oven at a first elevated temperature for a first drying period. The first elevated temperature may range from about <NUM> to about <NUM> - including all sub-ranges and temperature there-between. In some embodiments, the first elevated temperature may range from about <NUM> to about <NUM> - including all sub-ranges and temperature there-between. In some embodiments, the first elevated temperature may range from about <NUM> to about <NUM> - including all sub-ranges and temperature there-between.

The first drying period may range from about <NUM> seconds to about <NUM> seconds - including all sub-ranges and temperature there-between. The resulting face coating <NUM> may be present on the upper surface <NUM> of the body <NUM> in an amount ranging from about <NUM>/m<NUM> to about <NUM>/m<NUM> - including all amounts and sub-ranges there-between.

Referring now to <FIG> and <FIG>, the resulting building panel <NUM> may comprise the face coating <NUM> - whereby the first major surface <NUM> of the building panel <NUM> comprises the upper surface <NUM> of the face coating <NUM>. Thus, in the installed state, at least a portion of the upper surface <NUM> of the face coating <NUM> faces the active room environment <NUM>. The face coating <NUM> may be substantially continuous. The term "substantially continuous" means less than <NUM> % of the available surface area on the referenced surface contains pin-holing or blistering.

According to other embodiments, the building panel <NUM> may comprise a surface coating <NUM> applied to the side surface <NUM> of the body <NUM> to form an edge coating <NUM>. The edge coating <NUM> may comprise one or more of the previously discussed color pigments. Thus, the edge coating <NUM> may also be referred to herein as a color edge coating <NUM>.

The edge coating <NUM> may comprise an outer surface <NUM> opposite an inner surface <NUM>. The edge coating <NUM> has an edge coating thickness t<NUM> was measured from the outer surface <NUM> to the inner surface <NUM> of the edge coating <NUM>. The edge coating thickness t<NUM> may range from about <NUM> to about <NUM> - including all thicknesses and sub-ranges there-between. In a preferred embodiment, the edge coating thickness t<NUM> may range from about <NUM> to about <NUM> - including all thicknesses and sub-ranges there-between. The edge coating <NUM> (i.e., in the dry-state) may be present in an amount ranging from about <NUM>/m<NUM> to about <NUM>/m<NUM> - including all amounts and sub-ranges there-between.

The edge coating <NUM> may comprise a second pigment, a second dispersant, and a second binder. The second binder may be present in an amount ranging from about <NUM> wt. % to about <NUM> wt. % based on the total dry-weight of the edge coating <NUM> - including all amounts and sub-ranges there-between. The second binder may be thixotropic. The term "thixotropic" refers to a composition that has a high viscosity (e.g., <NUM>,<NUM> cps) at low-shear and a low viscosity (e.g., <NUM> cps) at high-shear. Non-limiting examples of thixotropic binder include polymers selected from polyvinyl alcohol (PVOH), aforementioned latex, acrylic polymer, polymaleic anhydride, or a combination of two or more thereof.

The second binder may be a thixotropic polymeric having a Tg that is less than room temperature ("Tm"). In a preferred embodiment, the second binder is a thixotropic polymeric binder having a Tg less than <NUM> - preferably less than <NUM>. The binder may be film-forming and having a minimum film-forming temperature of about <NUM>. The term "film-forming temperature" refers to the temperature at which a composition forms a film.

The second pigment may be present in an amount ranging from about <NUM> wt. % to about <NUM> wt. % based on the total dry-weight of the edge coating <NUM> - including all wt. % and sub-ranges there-between. The second pigment may be present in an amount ranging from about <NUM> wt. % to about <NUM> wt. % based on the total dry-weight of the edge coating <NUM> - including all wt. % and sub-ranges there-between. The second pigment may be present in an amount ranging from about <NUM> wt. % to about <NUM> wt. % based on the total dry-weight of the edge coating <NUM> - including all wt. % and sub-ranges there-between.

The second pigment may comprise one of the pigments previously listed as being suitable for the first pigment. In other embodiments, the second pigment may comprise one or more white pigments having a particle size ranging from about <NUM> to about <NUM> - including all sizes and sub-ranges there-between. In some embodiments, the second pigment may comprise one or more white pigments having a particle size ranging from about <NUM> to about <NUM> - including all sizes and sub-ranges there-between.

The second dispersant may be present in an amount ranging from about <NUM> wt. % to about <NUM> wt. % based on the total dry-weight of the edge coating <NUM> - including all wt. % and sub-ranges there-between. Like the first dispersant, the second dispersant may comprise a hydrophilic portion and a hydrophobic portion.

When the second pigment has a particle size in the same range as disclosed for the smaller first pigment, the second dispersant may comprise one or more compounds listed as being suitable for the first dispersant.

Referring now to <FIG>, when the second pigment <NUM> has a particle size ranging from about <NUM> to about <NUM>, the second dispersant <NUM> may comprise anionic polyacrylic dispersants wherein the ionic group <NUM> is located directly on the polymer backbone <NUM> of the second dispersant <NUM>. Together, the second pigment <NUM> and the second dispersant <NUM> form a second dispersible pigment <NUM>.

The edge coating <NUM> may be formed by applying an edge coating composition having a solids content ranging from about <NUM> wt. % to about <NUM> wt. % - including all amounts and sub-ranges there-between. The edge coating composition may be thixotropic. The edge coating composition may be thixotropic. The edge coating composition may have a viscosity ranging from about <NUM>,<NUM> cps to about <NUM>,<NUM> cps as measured by a Brookfield viscometer at <NUM> RPM using a #<NUM> spindle at room temperature - including all viscosities and sub-ranges there-between. The edge liquid-based coating composition may comprise water as the liquid carrier, wherein the liquid carrier comprises less than <NUM> wt. % of VOC solvent.

The edge coating composition may be applied to the body side surface <NUM> in an amount ranging from about <NUM>/m<NUM> to about <NUM>/m<NUM> - including all sub-ranges and values there-between. The edge coating composition may be applied to the side surface <NUM> of the body <NUM> by spray, roll, wheel coater, and vacuum coating.

The edge coating composition may be dried at an elevated temperature for a drying period - wherein the elevated temperature ranges from about <NUM> to about <NUM> - including all sub-ranges and temperature there-between. The drying period may range from about <NUM> seconds to about <NUM> seconds - including all sub-ranges and temperature there-between. The resulting edge coating <NUM> (i.e., in the dry-state) may be present in an amount ranging from about <NUM>/m<NUM> to about <NUM>/m<NUM> - including all amounts and sub-ranges there-between.

According to the embodiments where the building panel <NUM> comprises the edge coating <NUM>, the side surface <NUM> of the building panel <NUM> may comprise the edge coating <NUM>. Specifically, the side surface <NUM> of the building panel <NUM> may comprise the outer surface <NUM> of the edge coating <NUM>. Thus, the outer surface <NUM> of the edge coating <NUM> may for the upper portion 113a and the lower portion 113b of the side surface <NUM> of the building panel <NUM>. Specifically, the upper portion 113a of the side surface <NUM> may comprise an upper edge coating portion 231a and the lower portion 113b of the side surface <NUM> may comprise a lower edge coating portion 231b.

Although not pictured, some embodiments of the present invention include a building panel comprising a surface coating <NUM> comprising only the edge coating <NUM>. Specifically, the building panel <NUM> may comprise a first major surface opposite a second major surface and a side surface extending there-between. The side surface <NUM> of the building panel <NUM> may comprise the edge coating <NUM>, the first major surface <NUM> of the building panel <NUM> may comprise the upper surface <NUM> of the body <NUM> and the second major surface <NUM> of the building panel <NUM> may comprise the lower surface <NUM> of the body <NUM>.

Although not pictured, some embodiments of the present invention include a building panel comprising a surface coating <NUM>, wherein the surface coating <NUM> comprises only the face coating <NUM>. Specifically, the building panel <NUM> may comprise a first major surface <NUM> opposite a second major surface <NUM> and a side surface <NUM> extending there-between. The first major surface <NUM> of the building panel <NUM> may comprise the upper surface <NUM> of the face coating <NUM>, the second major surface <NUM> of the building panel <NUM> may comprise the lower surface <NUM> of the body <NUM>, and the side surface <NUM> of the building panel <NUM> may comprise the body side surface <NUM>.

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

Referring now to <FIG>, the building panel <NUM> may be installed according to the second variation, as described herein. The building panel <NUM> may be positioned such that the upper portion 513a of the side surface <NUM> is below the horizontal flange <NUM>, thereby extending into the active room environment <NUM>. In the second variation, the lower portion 513b of the side surface <NUM> is above the horizontal flange <NUM> extending into the plenum space <NUM>. In the second variation, the first major surface <NUM> and the upper portion 513a of the side surface <NUM> of the building panel <NUM> is exposed to the active room environment <NUM>. In the second variation, the lower portion 513b of the side surface <NUM> may be concealed from the active room environment <NUM>. The lower portion 513b of the side surface <NUM> may be adjacent to at least a portion of the vertical web <NUM> as viewed along a horizontal direction. The lower portion 513b of the side surface <NUM> as well as the second major surface <NUM> may be exposed to the plenum space <NUM>.

According to these embodiments, the upper portion 513a and the lower portion 513b may comprise the surface coating <NUM> - specifically, the first face coating <NUM>. According to these embodiments, the first major surface <NUM> may comprise the surface coating <NUM> - specifically, the edge coating <NUM>. Therefore, the surface coating <NUM> may be exposed to the active room environment on the first major surface <NUM> and the upper portion 513a of the side surface <NUM> of the building panel <NUM> in the installed state.

The invention will be described in greater detail by way of specific examples. The following examples are offered for illustrative purposes and are not intended to limit the invention in any manner.

The following experiment is directed to a high solids color coating composition of the present invention that may be used to form a coating with superior aesthetic properties. Coating compositions were prepared according to the following formulations set forth in Table <NUM>:.

The binder is carboxylated polyvinyl acetate homopolymer. Pigment <NUM> is calcium carbonate having a particle size of about <NUM>. Pigment <NUM> is kaolin having a particle size of about <NUM>. Pigment <NUM> is calcined diatomaceous earth having a particle size of about <NUM>.

The first dispersant is an anionic polymer dispersant having pendant side-chains extending from a polymer backbone wherein the anionic groups are located on the terminal ends of the pendant side-chains. The first dispersant comprises the anionic polymer dispersed in water at a solids content ranging from about <NUM> wt. % to about <NUM> wt. The additive includes a mixture of defoamer and biocide. The thickener includes hydroxyethylcellulose.

Each component (e.g., Pigments <NUM>-<NUM>, first dispersant, binder, etc.) may be provided as a solid or as a pre-made mixture with water in various solids content. Thus, to account for some of the coating composition components being pre-mixed with water, the total solids content of the overall coating composition in water is provided.

The viscosity of each of the coating compositions of Examples <NUM>-<NUM> as well as Comparative Example <NUM> were then measured using a Brookfield viscometer as various RPMs. The composition of each example was also allowed to sit for various periods of time - after which the stability of each composition was observed in the form of hard-packing, which refers to the presence of agglomeration of the pigments into hard packs (as compared to a uniform dispersion of the individual pigments throughout the carrier). The results are set forth in Table <NUM>.

As demonstrated by Table <NUM>, the coating composition of the present invention provides the desired viscosity while also providing superior stability of the pigments within the coating composition over time. Superior stability of the pigment in the coating composition translates to better color distribution in the resulting coating formed from the coating composition. As a result, coating compositions having higher solids contents can be achieved without sacrificing the desired aesthetic properties of the resulting coating.

The following experiment is directed to a high solids coating composition of the present invention that may be used to form a coating with superior aesthetic properties when using pigments having a particle size ranging from about <NUM> to about <NUM>,<NUM>. Coating compositions were prepared according to the following formulations set forth in Table <NUM>:.

The first dispersant is an anionic polymer dispersant having pendant side-chains extending from a polymer backbone wherein the anionic groups are located on the terminal ends of the pendant side-chains. The first dispersant liquid has a solids content ranging from about <NUM> wt. % to about <NUM> wt. % and comprises water as a carrier. The second dispersant is an anionic dispersant having anionic groups attached directly to the polymeric backbone and no pendant side-chains. The second dispersant liquid has a solids content of about <NUM> wt. % and comprises water as a carrier. The additive includes a mixture of defoamer, wetting agent, and biocide/antimicrobial agents. The thickener includes hydroxyethylcellulose.

Each component (e.g., Pigments <NUM>-<NUM>, first dispersant, second dispersant, etc.) may be provided as a solid or as a pre-made mixture with water in various solids content. Thus, to account for some of the coating composition components being pre-mixed with water, the total solids content of the overall coating composition in water is provided.

The viscosity of each of the coating compositions of Example <NUM> and Comparative Example <NUM> were then measured using a Brookfield viscometer as various RPMs. The results are set forth in Table <NUM>.

As demonstrated by Table <NUM>, the coating composition of the present invention provides the desired viscosity at much higher solids contends as compared to other anionic dispersants having the ionic group present directly on the polymer backbone.

Additionally, the enhanced dispersion of the pigments using the dispersant of the present invention is reflected in the superior drawdown color values. The drawdown color evaluations of each sample were measured and compared against each other. The color evaluations were performed by measured for a change in color value - i.e. "Delta E" (Δ E). Delta E value is measured by the following calculation: <MAT> wherein L<NUM>, a<NUM>, and b<NUM> are color values of Comp. <NUM>, measured using a Minolta Chroma Meter CR <NUM> from Minolta Corporation. The L<NUM>, a<NUM>, and b<NUM> values are the color values of Ex. <NUM> as measured by the Minolta Chroma Meter CR <NUM>. The color values are shown in Table <NUM>.

As demonstrated by Table <NUM>, the coating formed from the coating of Example <NUM> exhibits superior color values demonstrated by the ΔE being greater than <NUM>. Additionally, the enhanced dispersion of the pigments using the dispersant of the present invention is reflected in the superior gloss values. The gloss values are shown in Table <NUM>.

As demonstrated by Table <NUM>, the enhanced pigment dispersion of Example <NUM> (as compared to Comparative Example <NUM>) creates a better colored face coating that absorbs more incident light, thereby providing a less gloss surface and providing superior color appearance.

The following experiment is directed to a high solids coating composition of the present invention that may be used to form a coating with superior aesthetic properties when using pigments having a particle size ranging from about <NUM> to about <NUM>. Coating compositions were prepared according to the following formulations set forth in Table <NUM>:.

The binder is carboxylated polyvinyl acetate homopolymer. Pigment <NUM> includes calcium carbonate having a particle size of about <NUM>. Pigment <NUM> includes kaolin having a particle size of about <NUM>. Pigment <NUM> includes calcined diatomaceous earth having a particle size of about <NUM>. Pigment <NUM> includes carbon black having a particle size less than about <NUM>.

Two sets of viscosity measurements were performed on the compositions of Example <NUM> and Comparative Example <NUM>. The first set of viscosity measurements were performed immediately after the respective compositions were formed. Each sample was then allowed to sit undisturbed for a period of <NUM> hours, whereby the viscosity of each sample was then subjected to another viscosity test using a Brookfield viscometer as various RPMs. The drawdown color evaluations of each sample were also measured and compared against each other. The results are set forth in Table <NUM>.

As demonstrated by Table <NUM>, the coating composition of the present invention provides the desired viscosity stability over time at much higher solids contends as compared to other anionic dispersants having the ionic group present directly on the polymer backbone.

Additionally, the enhanced dispersion of the pigments using the dispersant of the present invention is reflected in the superior drawdown color values. The drawdown color evaluations of each sample were measured and compared against each other. The color evaluations were performed by measured for a change in color value - i.e. "Delta E" (Δ E) - wherein L<NUM>, a<NUM>, and b<NUM> are color values of Comp. <NUM>, measured using a Minolta Chroma Meter CR <NUM> from Minolta Corporation. The L<NUM>, a<NUM>, and b<NUM> values are the color values of Ex. <NUM> as measured by the Minolta Chroma Meter CR <NUM>. The color values are shown in Table <NUM>.

As demonstrated by Table <NUM>, the coating formed from the coating of Example <NUM> exhibits a change in color values demonstrated by the ΔE being greater than <NUM>. Additionally, the enhanced dispersion of the pigments using the dispersant of the present invention is reflected in the superior gloss values. The gloss values are shown in Table <NUM>.

Claim 1:
A coated building panel comprising:
a body comprising an upper surface opposite a lower surface and a side surface extending between the upper surface and the lower surface;
a surface coating atop the upper surface, the surface coating comprising:
inorganic pigment; and
an anionic polymeric dispersant comprising a polymer backbone and pendant side chains extending from the polymer backbone and wherein anionic groups are located on the terminal ends of the pendant side-chains;
wherein the surface coating comprises a liquid carrier in an amount less than about <NUM> wt. % based on the total weight of the surface coating.