Coating composition using glass particles as filler, coated non-woven mat, construction boards and processes for producing the same

Abstract

Coatings that include a glass-based filler instead of or in addition to a mineral based filler are disclosed. The coatings are suitable for application to fibrous nonwoven substrates. Because the glass-based filler can be produced from waste glass that might otherwise be disposed of in a landfill, the coatings promote increased sustainability.

Description

COATING COMPOSITION USING GLASS PARTICLES AS FILLER, COATED NON-WOVEN MAT, CONSTRUCTION BOARDS AND PROCESSES FOR PRODUCING THE SAMECROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to and all benefit of European Patent Application No. 23214083.0 filed on December 4, 2023, the entire disclosure of which is fully incorporated herein by reference.FIELD

[0002] The general inventive concepts relate to systems for and methods of using glass, in particular but not limited to milled recycled glass waste, as filler particles in nonwoven fiber mats. The invention is related to a coating composition for nonwoven mats that comprises a polymeric binder and a filler in which the inorganic mineral component has been replaced, at least partially, by glass particles, notably milled glass fibers or glass fiber-containing products. The invention is thus also about nonwoven mats coated or impregnated by said coating composition, as well as construction boards comprising such coated or impregnated nonwoven mats.BACKGROUND

[0003] Conventional nonwoven mats or veils include a fibrous web bound together by a suitable binder, and can be used in gypsum boards, polyiso boards, ceiling tiles, insulation panels, as well as flooring, wallpaper, pipe, and other composite applications. The fibrous web may include glass fibers. A nonwoven mat generally has a porous structure such that materials, particularly liquid materials, applied to the nonwoven mat tend to bleed through from one surface of the nonwoven mat to the opposing surface of the nonwoven mat. In certain applications, it may be desirable to utilize a nonwoven mat, but the porous structure of the nonwoven mat may be undesirable due to such bleed-through. Applying a coating composition (“coating”) that has filler particles (“filler”), for example a coating having a binder and a filler, to nonwoven mats is one way to reduce their porosity. Such coatings may be impregnated in the nonwoven mats such that some of the coating extends from one surface of the nonwoven mat toward, and in some instances to, an opposing surface of the nonwoven mat (“impregnated nonwoven mats”). Instead of being impregnated, some coatings may also remain on one surfaceof the nonwoven mat without substantially penetrating into the mat (“coated nonwoven mats”). Impregnated and coated nonwoven mats have many applications, such as facers for ceiling tiles, exterior sheathing boards, roofing boards and wall boards.

[0004] While many inorganic mineral fillers, for example calcium carbonate (“CaCCh”), aluminum trihydrate (“ATH”), huntite, kaolin, and wollastonite, have been used in coatings to form impregnated nonwoven mats and coated nonwoven mats, there remains an unmet need for new materials that can be used in place of such conventional fillers while maintaining the expected performances of the nonwoven mats in their respective applications. The present disclosure is directed to using glass waste to replace at least a portion of a conventional filler, to be used in such nonwoven mats. This use of glass waste provides many advantages, not the least of which is increased sustainability and recycled content.SUMMARY

[0005] In view of the above, systems for and methods of rendering glass waste suitable for use as filler in coatings applied to nonwoven fiber mats are disclosed. In many instances, the glass waste would otherwise be transported to and deposited in a landfill. In this regard, the glass waste can be considered to have a negative cost relative to other filler materials (e.g., calcium carbonate). Any suitable glass waste can be used, regardless of its origin. For example, the glass waste can be the result of scrap generated during the glass forming process (e.g., basement waste), scrap generated during product formation (e.g., chopped strand mat (“CSM”) waste), scrap created at the end of a product’s life (e.g., wind turbine blade replacement), or scrap from any composite material containing glass reinforcement such as panels or car parts. The systems and methods include processing (e.g., milling and sieving) the glass waste into filler particles that are similar in size and / or shape to conventional filler particles. When used in coatings for nonwoven mats, the inventive glass filler particles achieve comparable or better properties than conventional filler particles.

[0006] The general inventive concepts relate to using glass waste as a filler in nonwoven mats, through the use of those glass wastes as filler in the coating or impregnation compositions of those nonwoven mats. The glass waste can be sourced from glass which would otherwise need to be disposed of, thereby eliminating, or reducing, disposal costs as well as the costs of purchasing conventional fillers such as ATH in ceiling facers and CaCCh in gypsum boards. In some embodiments, the glass waste is the sole filler in the coating composition. In other embodiments, the glass waste replaces a portion (e.g., at least 5 % by dry weight, preferably atleast 10%, more preferably at least 15%) of a conventional filler in the coating composition. A further benefit is that use of glass waste as filler in coatings as described herein produces facers with comparable properties to facers having conventional fillers, such as porosity, opacity, and thickness in impregnated ceiling facers, and tensile strength, Cobb value, and wet tensile strength in gypsum boards, and / or results in the nonwoven mats promoting other desirable benefits such as increased sustainability.

[0007] The invention is thus first related to a coating composition comprising a polymeric binder and a filler, wherein said filler comprises from 5 to 100% by weight of glass particles and from 0 to 95% by weight of an inorganic mineral component.

[0008] The invention is also directed to a nonwoven mat comprising a nonwoven precursor mat coated or impregnated by the coating composition of the invention.

[0009] Another object of the invention is a construction board comprising a nonwoven mat attached to a core, wherein the nonwoven mat is as defined above, i.e. comprising a nonwoven precursor mat coated or impregnated by the coating composition of the invention, and the core is selected from the group consisting of a ceiling tile, gypsum board, building panel, insulation panel, and floorboard, preferably a gypsum board, insulation panel or a ceiling tile.

[0010] Still another object of the invention is the use of glass particles to replace at least partially the inorganic mineral filler of a coating composition comprising a polymeric binder and an inorganic mineral filler, for coating or impregnating a nonwoven mat.

[0011] Also, the invention is about a process for producing a coating composition according to the invention, comprising a step of mixing a polymeric binder with a filler, wherein said filler comprises from 5 to 100% by weight of glass particles; and from 0 to 95% by weight of an inorganic mineral component.

[0012] Last, the present invention is about a process for producing a coated or impregnated nonwoven mat wherein a nonwoven precursor mat is coated or impregnated with the coating composition of the invention.

[0013] To further illustrate various aspects of the general inventive concepts, several exemplary embodiments of using a glass-based filler in a coating and in fiber-based materials (e.g., nonwoven mats) are disclosed.

[0014] In one exemplary embodiment, a coating composition is disclosed. The coating composition comprises a polymeric binder and a filler.

[0015] “Coating composition” is encompassing both compositions aiming at coating substrates, in particular nonwoven mats or veils, that is to say that the composition fills only part of the substrate, typically less than 90% of the thickness of the substrate, resulting in an asymmetric build-up and impregnating substrates, in particular nonwoven mats or veils, that is to say that the composition substantially extends from one surface of the substrate toward, and in some instances to, an opposing surface of the substrate. Typically, more than 90% and up to 100% of the thickness of the substrate in filled with the coating composition, resulting in a symmetric build-up.

[0016] The polymeric binder can be an aqueous emulsion or solution of (co)polymers comprising at least one of the following monomers: styrene; (meth)acrylic acid or ester; alkyl (meth)acrylic acid or ester such as butyl acrylate, ethyl acrylate, methyl methacrylate, ethylhexyl acrylate; vinyl esters such as vinyl acetate, vinyl versatate; styrene-butadiene; vinyl alcohol; urea formaldehyde; starch based monomers; and mixtures thereof. Preferred polymeric binders are aqueous emulsions comprising at least one of the following monomers: styrene, acrylic acid esters, styrene-butadiene, vinyl alcohol and vinyl versatate.

[0017] In one embodiment of the coating composition of the invention, the filler further comprises an inorganic mineral component.

[0018] In the exemplary embodiments where the filler further comprises an inorganic mineral component, it is selected from the group consisting of aluminum trihydrate, calcium carbonate, magnesium carbonate, talc, vermiculite, antimony oxide, titanium dioxide, aluminum oxide, a clay, or a combination of any two or more of these substances. Preferably, the inorganic mineral component is either aluminum trihydrate or calcium carbonate.

[0019] In some exemplary embodiments, the glass particles and inorganic mineral component are present in the coating composition in a dry weight ratio in the range of 99:1 to about 1 :99.

[0020] In some exemplary embodiments, the glass particles and inorganic mineral component are present in the coating composition in a dry weight ratio in the range of 9: 1 to about 1 :9, more preferably in the range of 4: 1 to about 1 :4, more preferably about 1 : 1.

[0021] According to a preferred embodiment of the coating composition of the invention, the filler comprises from 10 to 90% by dry weight of glass particles based on the total dry weight of filler, preferably from 15 to 75%, and from 10 to 90% by dry weight of an inorganic mineral component based on the total dry weight of filler, preferably from 25 to 85%.

[0022] In some exemplary embodiments, more than half of the filler of the coating composition by dry weight is comprised of the glass particles.

[0023] In some exemplary embodiments, less than half of the filler of the coating composition by dry weight is comprised of the glass particles.

[0024] In one exemplary embodiment, a coating composition is disclosed. The coating composition comprises a binder and a filler, wherein the binder is selected from the group consisting of aqueous emulsions or solutions of (co)polymers comprising at least one of the following monomers: styrene; (meth)acrylic acid or ester; alkyl (meth)acrylic acid or ester such as butyl acrylate, ethyl acrylate, methyl methacrylate, ethylhexyl acrylate; vinyl esters such as vinyl acetate, vinyl versatate; styrene-butadiene; vinyl alcohol; urea formaldehyde; starch based monomers; and mixtures thereof, and wherein the filler comprises glass particles and non-glass particles.

[0025] In some exemplary embodiments, the non-glass particles comprise an inorganic mineral component.

[0026] In some exemplary embodiments, the glass particles and inorganic mineral component are present in the coating composition in a dry weight ratio in the range of 9: 1 to about 1 :9, more preferably in the range of 4: 1 to about 1 :4, more preferably about 1 : 1.

[0027] According to a preferred embodiment of the coating composition of the invention, the filler comprises from 10 to 90% by dry weight of glass particles based on the total dry weight of filler, preferably from 15 to 75%, and from 10 to 90% by dry weight of an inorganic mineral component based on the total dry weight of filler, preferably from 25 to 85%.

[0028] In some exemplary embodiments, the glass particles comprise at least one of H glass, E glass, E-CR glass, C glass, or boron.

[0029] The glass particles used in the coating composition of the invention have a particle size distribution with a d50 that is advantageously ranging from 1 to 30 microns. Multiple particle size distributions of different glass particles might be desirable in some instances. For example, a first glass particle of particle size distribution with a d50 that is ranging from 1 to 10 microns can be mixed with a second glass particle, of same or from different source, of particle size distribution with a d50 that is ranging from 10 to 30 microns.

[0030] In a preferred embodiment of the invention, the glass particles are milled glass fibers or milled glass fiber-containing products.

[0031] In this embodiment, the milled glass fibers or milled glass fiber-containing products may be milled scrap or wastes from glass fiber manufacturing processes or from glass fibercontaining products manufacturing processes, such as scrap or wastes from composites manufacturing processes, or are milled end-of-life glass fiber-containing products such as composites products.

[0032] Still in this particular embodiment, the milled glass fiber-containing products can be milled end-of-life glass fiber-containing products such as composites products, preferably wind turbine blades.

[0033] End-of-life composites products are generally made of resin, glass fibers and optionally fillers. The resin usually represents from about 10 to 50%, preferably from 20 to 40% by weight of the total weight of the composite, the glass fibers usually represent from about 50 to 90%, preferably from 80 to 60% by weight of the total weight of the composite. Those end-of life composites products, such as wind turbine blades are advantageously treated to remove at least 70 %, preferably at least 80% by weight of the resin and recover the glass fibers for further use in the coating composition of the invention. This treatment can be a pyrolysis, a solvolysis, or any other known technique that allow the separation of the resin and the glass fibers. The glass fibers that are obtained from this treatment are then milled.

[0034] Glass fibers scrap or wastes from glass fiber manufacturing processes can be the result of scrap generated during the glass forming process (e.g., basement waste). Those scrap orwastes have usually a level of LOI (organic content) of about 0.1 to 5%, preferably 0.2 to 2% by weight based on the total weight of the glass fiber.

[0035] Glass fiber-containing products can be scrap generated during product formation (e.g., chopped strand mat (“CSM”) waste, fabrics wastes or nonwoven mat wastes), scrap created at the end of a product’s life (e.g., wind turbine blade replacement), or scrap from any composite material containing glass reinforcement such as panels or car parts. The scrap or wastes from CSM production have usually a level of LOI (organic content) of about 1 to 15%, preferably 2 to 10% by weight based on the total weight of the glass fiber. For fabrics, the level of LOI is ranging from 30 to 50% by weight before treatment to remove the organics and 0.1 to 30% by weight after treatment to remove the organics. For nonwovens the level of LOI is generally from 5 and 60% by weight before treatment to remove the organics and 0.1 to 30% by weight after treatment to remove the organics. For Wind Turbine blades, the level of LOI is ranging from 10 to 50% by weight before treatment to remove the organics and 0.1 to 30% by weight after treatment to remove the organics.

[0036] In some exemplary embodiments, the glass particles were obtained from production waste.

[0037] In some exemplary embodiments, the glass particles were obtained from a wind turbine blade.

[0038] In some exemplary embodiments, the glass particles were milled.

[0039] In some exemplary embodiments, the glass particles were subjected to at least one of pyrolysis or solvolysis.

[0040] In some exemplary embodiments, the coating composition further comprises at least one of a flame retardant, hydrophobic agent, defoamer, thickener, or dispersing agent.

[0041] In some exemplary embodiments, the coating composition is applied to a nonwoven mat.

[0042] Thus, another object of the present invention is a nonwoven mat comprising a nonwoven precursor mat that is coated or impregnated by the coating composition as described above.

[0043] The nonwoven precursor mat is advantageously a nonwoven glass mat. Nonwoven fiber glass mat are preferred and they can include at least two distinct fiber types, which differ from one another by composition, diameter, and / or length.

[0044] The nonwoven glass mat is made of chopped glass fibers that are randomly oriented to form a veil of glass. There are several known techniques to produce those precursor mats.

[0045] The precursor mat may be prepared in a method comprising the steps of (i) providing an aqueous mixture comprising glass fibers, and a precursor binder; (ii) forming a dispersion of the aqueous mixture; (iii) depositing the aqueous dispersion to form a wetlaid web of glass fibers, and precursor binder; and (iv) drying the wetlaid web of glass fibers, and precursor binder to form the precursor mat.

[0046] Alternatively, the precursor mat may be prepared in a method comprising the steps of (i) providing an aqueous mixture comprising glass fibers; (ii) depositing the aqueous mixture to form a wetlaid web of glass fibers; (iii) applying an aqueous solution or dispersion of a precursor binder to the wetlaid web of glass fibers, to form a wetlaid web of glass fibers, and precursor binder; and (iv) drying the wetlaid web of glass fibers, and precursor binder to form the precursor mat.

[0047] The precursor binder may be applied to the web of glass fibers by a suitable binder applicator, such as a spray applicator or a curtain coater.

[0048] The precursor mat may be formed by a wet-laid process. The non-woven mat is formed by a wet-laid process, which involves forming an aqueous dispersion, slurry, or mixture of discrete fibers in a mix tank filled with various optional components (sometimes referred to as white water). The aqueous mixture therefore comprises the glass fibers, the precursor binder (or combination thereof) and water, and optionally other components such as surfactants, viscosity modifiers, defoaming agents, lubricants, biocides, and / or other chemical agents.

[0049] The dispersion of the aqueous mixture may be obtained by any suitable means provided a uniform or substantially uniform distribution of the glass fibers in the aqueous medium is produced. A uniform distribution of the glass fibers may be produced. Alternatively, a substantially uniform distribution of the glass fibers may be produced. The dispersion may be obtained by a high shear mixing apparatus, such as a rotor / stator mixer.

[0050] The precursor binder (or combination thereof) may optionally contain conventional additives for the improvement of process and product performance such as dyes, oils, biocides, fillers, colorants, UV stabilizers, coupling agents (e.g., aminosilanes), lubricants, wetting agents, surfactants, and / or antistatic agents.

[0051] The precursor binder (or combination thereof) may be added at any suitable point in the preparation of the aqueous mixture. For example, it (or combination thereof) may be added before, after, or at the same time as the glass fibers.

[0052] The precursor binder may be a liquid or solid. When the first binder is a powder, the powdered binder may facilitate co-casting with the glass fibers in the aqueous solution.

[0053] The aqueous fiber dispersion or slurry may then be processed into a wet-laid mat according to any number of conventional methods known in the art. For example, the aqueous fiber dispersion or slurry is deposited onto a moving screen or conveyor, on which the majority of the water drains through, leaving a randomly oriented fiber web. The water may be removed from the web by a conventional vacuum or air suction system.

[0054] The wetlaid web is passed through at least one drying oven to remove remaining water and cure the precursor binder composition.

[0055] The fiber glass mat may be further dried by a vacuum slot or other drying means.

[0056] The formed precursor mat that emerges from the oven is an assembly of randomly oriented, dispersed, individual glass fibers. The fiber mat may be rolled onto a take-up roll for storage or later use.

[0057] In some exemplary embodiments, the coating composition extends into a thickness of the nonwoven mat.

[0058] In some exemplary embodiments, the coating composition extends through a thickness of the nonwoven mat.

[0059] In one exemplary embodiment, a method of forming a glass-based filler is disclosed. The method comprises supplying a glass material comprising a plurality of glass fibers, wherein the glass fibers have an average aspect ratio greater than 20 and processing the glassfibers to form a plurality of glass particles, wherein the glass particles have an average aspect ratio less than 2.

[0060] In some exemplary embodiments, the processing of the glass fibers includes milling the glass fibers.

[0061] In some exemplary embodiments, the method further comprises cleaning the glass fibers.

[0062] In some exemplary embodiments, the method further comprises subjecting the glass fibers to at least one of pyrolysis or solvolysis.

[0063] In some exemplary embodiments, the glass particles comprise at least one of H glass, E glass, E-CR glass, C glass, or boron.

[0064] In some exemplary embodiments, the glass particles are blended with an inorganic mineral filler to form a coating composition.

[0065] In one exemplary embodiment, a coated nonwoven mat is disclosed. The coated nonwoven mat comprises a plurality of glass fibers held together by a binder to form a mat and a coating applied to the mat, wherein the coating includes glass filler particles.

[0066] In some exemplary embodiments, the coating further comprises an inorganic mineral component.

[0067] In some exemplary embodiments, the inorganic mineral component comprises aluminum trihydrate.

[0068] In some exemplary embodiments, the inorganic mineral component comprises calcium carbonate.

[0069] In some exemplary embodiments, the glass filler particles and inorganic mineral component are present in the coating in a dry weight ratio in the range of 99: 1 to 1 :99.

[0070] In some exemplary embodiments, the glass filler particles and inorganic mineral component are present in the coating in a dry weight ratio in the range of 9: 1 to 1 :9.

[0071] In some exemplary embodiments, the coating extends into a thickness of the coated nonwoven mat.

[0072] In some exemplary embodiments, the coating extends through a thickness of the coated nonwoven mat.

[0073] In some exemplary embodiments, the coated / impregnated nonwoven mat has a Gurley porosity in the range of about 10 s / 300 mL to about 1,000 s / 300 mL.

[0074] In some exemplary embodiments, the coated / impregnated nonwoven mat has a Gurley porosity of the mat is in the range of about 10 s to about 1,000 s.

[0075] In some exemplary embodiments, the coated / impregnated nonwoven mat has an opacity of about 20 to about 100.

[0076] In some exemplary embodiments, the coated / impregnated nonwoven mat has a thickness of about 0.2 mm to about 1 mm.

[0077] Another object of the present invention is a construction board comprising a nonwoven mat attached to a core, wherein the nonwoven mat is defined above (coated or impregnated with the coating composition of the invention) and the core is selected from the group consisting of a ceiling tile, gypsum board, building panel, insulation panel, and floorboard, preferably a gypsum board or a ceiling tile.

[0078] In some exemplary embodiments, the coated nonwoven mat is attached to a core.

[0079] In some exemplary embodiments, the core is a gypsum board.

[0080] Still another object of the present invention is the use of glass particles to replace at least partially (at least 5% by dry weight based on the total dry weight of the filler, preferably at least 10%, more preferably at least 15%, and up to 100%) the inorganic mineral filler of a coating composition comprising a polymeric binder and an inorganic mineral filler, for coating or impregnating a nonwoven mat.

[0081] In this use, the glass particles are as defined above, that is to say that they can be milled and they can be obtained from scrap or wastes from glass fiber manufacturing processes or from glass fiber-containing products manufacturing processes, such as scrap or wastes fromcomposites manufacturing processes, or are obtained from end-of-life glass fiber-containing products such as composites products.

[0082] Another object of the present invention is a process for producing the coating composition of the invention, comprising a step of mixing a polymeric binder with a filler, wherein said filler comprises from 5 to 100% by dry weight of glass particles and from 0 to 95% by dry weight of an inorganic mineral component, based on the total dry weight of the filler.

[0083] In this process the specific embodiments described above applying to the coating composition, polymeric binder, the filler and the glass particles are also applicable.

[0084] In this process, before the mixing step, a milling step can be performed on glass fibers or glass fiber-containing products, such as scrap or wastes from glass fiber manufacturing processes or from glass fiber-containing products manufacturing processes, such as scrap or wastes from composites manufacturing processes, or on end-of-life glass fiber-containing products such as composites products to produce the glass particles, resulting in the glass particles being in the form of milled glass fibers or milled glass fiber-containing products.

[0085] The milling step is generally performed to reduce the particle size distribution d50 of the glass fibers up to an appropriate d50 ranging from 1 to 30 microns, preferably 1 to 20 microns.

[0086] In this process, before the milling step, the glass fibers, glass fiber-containing products or end-of-life glass fiber-containing products can be subject to a cleaning step to remove the organic part attached to said glass fibers or glass fiber-containing product or end-of-life glass fiber-containing products, typically through a pyrolysis or solvolysis step.

[0087] In one exemplary embodiment, a method of forming a coating composition is disclosed. The method comprises blending a filler into a polymeric binder composition, wherein the filler comprises powdered glass and optionally an inorganic mineral component.

[0088] In some exemplary embodiments, the inorganic mineral component is aluminum trihydrate.

[0089] In some exemplary embodiments, the inorganic mineral component is calcium carbonate.

[0090] In some exemplary embodiments, the powdered glass and inorganic mineral component are present in the coating composition in a dry weight ratio in the range of 99:1 to 1 :99, preferably 95:5 to 5:95.

[0091] In some exemplary embodiments, the powdered glass and inorganic mineral component are present in the coating composition in a dry weight ratio in the range of 9: 1 to 1 :9.

[0092] In some exemplary embodiments, the powdered glass comprises at least one of H glass, E glass, E-CR glass, C glass, or boron.

[0093] Last, the invention is related to a process for producing a coated or impregnated nonwoven mat wherein a nonwoven precursor mat is coated or impregnated with the coating composition of the invention.

[0094] In this process the specific embodiments described above applying to the coating composition, nonwoven precursor mat and coating or impregnation techniques are also applicable.

[0095] Other aspects and features of the general inventive concepts will become more readily apparent to those of ordinary skill in the art upon review of the following description of various exemplary embodiments in conjunction with the accompanying figures.BRIEF DESCRIPTION OF THE DRAWINGS

[0096] The general inventive concepts, as well as embodiments and advantages thereof, are described below in greater detail, by way of example, with reference to the drawings in which:

[0097] Figure 1 is a diagram that illustrates the transformation of glass waste into filler particles to be used in a coating composition applied to impregnated nonwoven mats and coated nonwoven mats.

[0098] Figure 2A is a graph showing the porosity of impregnated ceiling facers produced from a coating composition comprising glass-based filler, where the glass-based filler replacedeither 25 % or 50 % of the ATH in the conventional coating by dry weight and was obtained from milled basement waste.

[0099] Figure 2B is a graph showing the porosity of impregnated ceiling facers produced from a coating composition comprising glass-based filler, where the glass-based filler replaced either 25 % or 50 % of the ATH in the conventional coating by dry weight and was obtained from milled CSM waste.

[0100] Figure 3 A is a graph showing the opacity of impregnated ceiling facers produced from a coating composition comprising glass-based filler, where the glass-based filler replaced either 25 % or 50 % of the ATH in the conventional coating by dry weight and was obtained from milled basement waste.

[0101] Figure 3B is a graph showing the opacity of impregnated ceiling facers produced from a coating composition comprising glass-based filler, where the glass-based filler replaced either 25 % or 50 % of the ATH in the conventional coating by dry weight and was obtained from milled CSM waste.

[0102] Figure 4A is a graph showing the thickness of impregnated ceiling facers produced from a coating composition comprising glass-based filler, where the glass-based filler replaced either 25 % or 50 % of the ATH in the conventional coating by dry weight and was obtained from milled basement waste.

[0103] Figure 4B is a graph showing the thickness of impregnated ceiling facers produced from a coating composition comprising glass-based filler, where the glass-based filler replaced either 25 % or 50 % of the ATH in the conventional coating by dry weight and was obtained from milled CSM waste.

[0104] Figure 5 is a graph showing the Cobb value of gypsum facers produced from a coating composition comprising glass-based filler, where the glass-based filler replaced either 25 % or 50 % of the CaCCh in the conventional coating by dry weight and was obtained from milled basement waste.

[0105] Figure 6 A is graph showing the thickness of gypsum facers produced from a coating composition comprising glass-based filler, where the glass-based filler replaced either 25 % or50 % of the CaCCh in the conventional coating by dry weight and was obtained from milled basement waste.

[0106] Figure 6B is graph showing the thickness of gypsum facers produced from a coating composition comprising glass-based filler, where the glass-based filler replaced either 25 % or 50 % of the CaCCh in the conventional coating by dry weight and was obtained from milled CSM waste.

[0107] Figure 7A is a graph showing the tensile strength of gypsum facers produced from a coating composition comprising glass-based filler, where the glass-based filler replaced either 25 % or 50 % of the CaCCh in the conventional coating by dry weight and was obtained from milled basement waste.

[0108] Figure 7B is a graph showing the tensile strength of gypsum facers produced from a coating composition comprising glass-based filler, where the glass-based filler replaced either 25 % or 50 % of the CaCCh in the conventional coating by dry weight and was obtained from milled CSM waste.DETAILED DESCRIPTION

[0109] Unless defined otherwise, all technical and scientific terms used herein have the same meanings as commonly understood by one of ordinary skill in the art to which this invention belongs. The term “about,” as used herein to modify any numerical values, encompasses the specific numerical value(s) without any modification, as well as reasonable deviations that still achieve the particular purpose associated with the values.

[0110] All references, publications, patents, patent applications, and commercial materials mentioned herein are incorporated herein by reference for all purposes including for describing and disclosing the methodologies which are reported in the publications which might be used in connection with the invention. Nothing herein is to be construed as an admission that the invention is not entitled to antedate such disclosure by virtue of prior invention.

[0111] Several illustrative embodiments will be described in detail with the understanding that the present disclosure merely exemplifies the general inventive concepts. Embodiments encompassing the general inventive concepts may take various forms and the general inventive concepts are not intended to be limited to the specific embodiments described herein.

[0112] The general inventive concepts encompass the use of glass-based filler particles in coatings for nonwoven fiber mats. The glass-based filler particles are created by processing (e.g., milling) a glass material, such as a waste or recycled glass material. The coatings formed with the glass-based filler particles can be used with any suitable nonwoven fiber mat including, but not limited to, a fiberglass mat formed by a wet-laid process. In some exemplary embodiments, the nonwoven fiber mat includes at least two distinct fiber types, which differ from one another by composition, diameter, and / or length.

[0113] Glass fiber containing products can be scrap generated during product formation (e.g., chopped strand mat (“CSM”) waste, fabric wastes or nonwoven mat wastes), scrap created at the end of a product’s life (e.g., wind turbine blade replacement), or scrap from any composite material containing glass reinforcement such as panels or car parts. Glass fiber containing products can further include resin from, for example, sizings, binders, and coatings. CSM waste, fabric waste, or nonwoven mat waste can also include fibers such as, for example, polymeric or natural fibers. Glass fibers scrap or wastes from glass fiber manufacturing processes can be the result of scrap generated during the glass forming process (e.g., basement waste).

[0114] Those scrap or wastes have usually a level of LOI (organic content) of about 0.1 to 5%, preferably 0.2 to 2% by weight based on the total weight of the glass fiber. The scrap or waste from CSM production have usually a level of LOI (organic content) of about 1 to 15%, preferably 2 to 10% by weight based on the total weight of the glass fiber. For fabrics, the level of LOI is ranging from 30 to 50% by weight before treatment to remove the organics and 0.1 to 30% by weight after treatment to remove the organics. For nonwovens the level of LOI is generally from 5 and 60% by weight before treatment to remove the organics and 0.1 to 30% by weight after treatment to remove the organics. For wind turbine blades, the level of LOI is ranging from 10 to 50% by weight before treatment to remove the organics and 0.1 to 30% by weight after treatment to remove the organics.

[0115] FIG. 1 illustrates a general method of creating a coating composition including glassbased filler particles. The coating composition can be used to form impregnated nonwoven mats and / or coated nonwoven mats to be used with ceiling tiles and gypsum boards. The glass can come from any suitable source. In some exemplary embodiments, the glass is glass waste from industrial processes and is milled to have a particle size distribution with a d50 of about7 m to about 11pm, as measured using laser granulometry. Table 1 lists the dlO, d50, and d90 values of the milled basement waste and milled edges waste. In some exemplary embodiments, the particle size distribution can be described by a dlO of about 2 pm, a d50 of about 7 pm, and a d90 of about 18 pm. In other exemplary embodiments, the particle size distribution can be described by a dlO of about 4 pm, a d50 of about 11 pm, and a d90 of about 30 pm. These particle size distributions are comparable to particle size distributions using conventional fillers. When the filler particles disclosed herein have a size distribution comprising a d50 larger than about 15 pm, the top layer of the coating will be less smooth, leading to a nonwoven mat with inferior aesthetics. These larger particles may also produce inhomogeneities in the coating, leading to nonwoven mats with inconsistent and / or less favorable properties such as tensile strength or porosity. On the other hand, a particle distribution size with a d50 lower than about 1 pm can be difficult to process. This is due to the smaller particles’ tendency to agglomerate and their lower weight, which results in them producing dust. These smaller particles can also increase the viscosity of the coating.

[0116] The average circularity of the glass particles is provided in Table 1. Circularity may be measured using image analysis-based particle analysis using scanning electron microscope (SEM) images. A circularity value of 1.0 indicates a perfect circle. As the circularity value approaches 0.0, it indicates an increasingly elongated polygon. The average circularity of the basement waste was 0.55 and the average circularity of the CSM waste was 0.60. In comparison, the average circularity of conventional filler particles ranges from about 0.6 to 0.7.

[0117] Glass processing, which is optional, can include milling and sieving (for example, sieving to less than about 60 pm as measured with a CAMsizer) or other processes that make the glass waste suitable for use as a filler and reduce the waste glass to a desired morphology (e.g., particle size and / or shape) and to a morphology similar to that of conventional fillers. Some embodiments can include pyrolysis, solvolysis, or other processes to extract glass as part of glass the processing, for example when the waste glass is recovered from glass-reinforced materials with resins such as windmill blades or car parts.

[0118] After processing, the glass can be blended or mixed with other components of a coating composition, based on the desired ratio of glass particles to non-glass particles (e.g., 1 :0, 1 : 1, 1 :2, 1 :3, etc.). In certain exemplary embodiments, the ratio of glass particles to non-glass particles is 1 : 1. In other exemplary embodiments, the ratio of glass particles to non-glass particles is 1 :3.

[0119] The coating composition is created by mixing a binder composition with a filler. Suitable examples of binder compositions, not intended to be limiting, include formaldehyde- free (or no-added formaldehyde (“NAF”)) binders, such as carboxyl-based binders, polyvinyl alcohol-based binders, carbohydrate-based binders, acrylic, styrene acrylic, butyl acrylate, ethylacrylate, methylmetacrylate, ethylhexylacrylate, vinylversatate, styrene-butadiene, acrylic acid, polyvinylalcohol, polyvinylacetate, and urea formaldehyde binder compositions, as well as biobased binders such as starches, lignins, carbohydrates, proteins, or fats. Biobased binders, in particular, are environmentally friendly. Bio-based binder compositions are described in more detail in U.S. Pat. Publication No. 2011 / 0086567 to Hawkins et al.. filed October 8, 2010, the entire contents of which are expressly incorporated herein by reference.

[0120] In some embodiments, the glass particles are mixed into the coating composition after some, or all, of the other components of the filler have already been mixed together. In some embodiments, including for example in a coating used to impregnate a mat, the glass can be added directly into the coating composition. In other embodiments, including for example in a coating that will not impregnate a mat, the glass can be mixed with water and a dispersing agent, forming a premix, wherein the premix is then mixed into the coating composition. The coating composition optionally includes additional flame retardants, hydrophobic agents, and coating additives such as defoamers, thickeners and dispersing agents.

[0121] After mixing, the coating composition is applied to the nonwoven mat. In some embodiments, such as some coated nonwoven mats, the coating composition is applied to the nonwoven mat via a “knife-over-roll coating” process, whereby a knife blade is suspended above a roller. The knife does not touch the substrate (the precursor mat, the mat to which the coated will be applied) directly. The thickness of the coating layer is controlled by the gap between the precursor mat and the knife, which is determined by adjusting the gap between the roller and the blade. Thereafter, the nonwoven mat with coating applied thereto is dried and cured.

[0122] In other embodiments, such as some impregnated nonwoven mats, the coating composition is applied using a side-press which comprises two rollers in a horizontal plane that move towards each other. In the space between the rollers, the coating is applied. Theimpregnation of the nonwoven mat takes place by leading the precursor mat through the coating and a small gap between the two rollers of the side press.

[0123] This is followed by removing excess coating, drying, and curing the nonwoven mat with coating applied thereto.

[0124] In embodiments, a nonwoven mat coated with the coatings described herein may exhibit comparable or even improved fire resistance as compared to an otherwise identical nonwoven mat coated with a coating including only inorganic filler. In particular, although the partial replacement of the inorganic filler with glass-based filler introduces organics to the nonwoven mat, self-extinguishability may increase and the fire propagation may decrease for nonwoven mats coated with the coatings including glass-based filler.

[0125] This invention increases the sustainability of nonwoven mats and the coatings applied thereto. Additionally, being able to replace a primary commercial filler component with a material that would otherwise be disposed of increases the sustainability of the production process.EXAMPLESExample 1

[0126] The inventors oversaw multiple studies involving two sources of recycled postindustrial glass: (1) recycled glass from multi-end roving forming glass (“basement waste” or “spaghetti waste”) that was subsequently milled in a ball mill and (2) recycled glass from chopped strand mat (CSM) edges waste (“CSM edges waste” or “CSM edges” or “edges waste”) that was subsequently milled in a ball mill (see Table 1). The ball mill was a lab scale ball mill and was filled with the glass waste and metal balls in a ratio of about 1 :2. In the basement waste, the fibers were milled lengthwise as well as across the diameter. The input material for milling started from fibers formed using a 20 mm screen. The diameter of the resulting milled glass particles was approximately equal to the length of the resulting milled glass particles in 100 % of the glass particles (within one order of magnitude), so essentially all of the glass particles resulting from the milling had an aspect ratio of about 1. In the CSM waste, the fibers were milled lengthwise as well as across the diameter. The input material for milling started from fibers formed using a 20 mm screen. The diameter of the resulting milledglass particles was approximately equal to the length of the resulting milled glass particles in approximately 98 % to 99 % of the glass particles (within one order of magnitude), so having an aspect ratio of about 1, and the length of the resulting milled glass particles was approximately 3 to 4 times its diameter in approximately 1 % to 2 % of the milled glass particles (within one order of magnitude), so having an aspect ratio of 3 to 4.Table 1

[0127] As expected, the basement waste exhibited a lower loss on ignition (“LOI”) than the CSM edges. LOI, per the ISO 1887 method, is the reduction in weight experienced by the fibers after heating them to a temperature sufficient to burn or pyrolyze the resin and other organic content from the fibers. The LOI of the basement waste was 0.46 % and the LOI of the CSM edges was 3.84 %, resulting in the basement waste requiring less time to be milled. The LOI of the waste glass may vary from about 0.2 % to 10 %. After milling, both waste sources were treated through an alumina ball mill and did not show any metallic magnetic particles.

[0128] As illustrated in Table 2, coatings comprising glass filler particles were applied to two types of nonwoven products: impregnated ceiling facers and coated (but not impregnated) gypsum facers. Some impregnated ceiling facers conventionally use ATH as a primary filler ingredient. Of the total amount by weight of dry ATH in the conventional coating, 25 % by weight of total dry was replaced with milled basement waste to form a coating used to study impregnated ceiling facers. Likewise, of the total amount of dry ATH in the conventional coating, 50 % by weight of total dry ATH was replaced with milled basement waste to form a coating used to study impregnated ceiling facers. The same was done with samples of CSM edges replacing the basement waste. 1 % by weight of total dry content in the coating of a dispersion agent was also added to each glass sample to be added to each coating. The requisiteamount of water was added to obtain the same total dry content as the conventional coating. Using a foulard, a 50 g / m2base veil was impregnated to become a 180g / m2end product and the impregnated ceiling facer was dried.

[0129] Some gypsum facers conventionally use CaCCh as a primary filler ingredient. Also as shown in Table 2, of the total amount of dry CaCCh in the conventional coating, 25 % by weight of total dry CaCCL was replaced with milled basement waste to form a coating used to study gypsum facers. Likewise, of the total amount of dry CaCCh in the conventional coating, 50 % by weight of total dry CaCCh was replaced with milled basement waste to form a coating used to test gypsum facers. The same was done with samples of the CSM edges replacing the basement waste. The requisite amount of water was added to obtain the same total dry content as the conventional coating. Using a lab coater, an 85 g / m2base veil was coated to become a 330 g / m2end product and the coated gypsum facer was dried.

[0130] Weight end (g / m2) refers to the area weight of the final, coated nonwoven mat (including the weight of the coating and of the precursor mat). In some coated nonwoven mats, the (non-impregnated) coating results in a mat with an asymmetric structure. In some impregnated nonwoven mats, the coating may extend from one surface of the nonwoven mat toward, and in some instances to, an opposing surface of the nonwoven mat, resulting in a mat with a symmetric structure. Typically, for nonwoven mats having fillers, the weight end is higher than the weight of the precursor mat, and the ratio between the weight of the precursor mat to the weight end can vary between about 1 : 1 to 1 :7.Table 2

[0131] It is generally desirable that ceiling facers are white, opaque, reflect light, and have a low porosity but one that is open enough to permit the passage of sound waves allowing for advantageous acoustics. Therefore, the opacity, whiteness (light reflection), and porosity of a mat are particularly important in ceiling tile applications. Fire protection is also an important feature of ceiling facers. Flame propagation testing via the “45-degree angle test” was conducted, where a coated nonwoven mat is placed in a flame having a temperature of about 1,000 degrees Celsius at an angle of 45 degrees for 30 seconds. The sample is evaluated on its ability to self-extinguish the flame and on the propagation of the flame. It was found that the flame was self-extinguishable and did not propagate in the nonwoven mats comprising glass filler.

[0132] Porosity was measured using ISO9237 at a pressure of 100 Pa. FIG. 2A shows the porosity of impregnated ceiling facers produced from a coating composition comprising glassbased filler, where the glass-based filler replaced either 25 % or 50 % of the ATH in the conventional coating by dry weight and was obtained from milled basement waste. As FIG. 2A illustrates, there were only moderate differences in porosity in facers with basement wastebased filler replacing both 25 % and 50 % of the ATH by dry weight. FIG. 2B shows the porosity of impregnated ceiling facers produced from a coating composition comprising glassbased filler, where the glass-based filler replaced either 25 % or 50 % of the ATH in the conventional coating by dry weight and was obtained from milled CSM waste. As FIG. 2B illustrates, there were only moderate differences in porosity in facers with CSM waste based- filler replacing 25 % and 50 % of the ATH by dry weight as well. The coating composition comprising basement waste-based filler particles resulted in facers with higher porosities (leading to more open facers) than those with a coating comprising CSM waste based-filler particles. Facers produced from the inventive glass-based filler demonstrated comparable porosities to facers formed with conventional filler coatings.

[0133] In terms of another important property of impregnated ceiling facers, opacity, the facers produced with the inventive glass-based fillers disclosed herein also achieve comparable results to those produced with conventional coatings, as illustrated by FIG. 3A and FIG. 3B. Opacity was quantified by obtaining the ratio of L* (according to CIE LAB) on a black and on a white background and multiplying by 100 %. FIG. 3 A shows the opacity of impregnated ceiling facers produced from a coating composition comprising glass-based filler, where the glass-based filler replaced either 25 % or 50 % of the ATH in the conventional coating by dryweight and was obtained from milled basement waste. FIG. 3B shows the opacity of impregnated ceiling facers produced from a coating composition comprising glass-based filler, where the glass-based filler replaced either 25 % or 50 % of the ATH in the conventional coating by dry weight and was obtained from milled CSM waste. The opacity achieved by the facers described by both FIG. 3A and FIG. 3B is comparable to that of the facers with conventional filler.

[0134] Thickness of the impregnated or coated nonwoven mat was measured by a Thwing- Albert testing machine, using ISO534. FIG. 4A shows the thickness of impregnated ceiling facers produced from a coating composition comprising glass-based filler, where the glassbased filler replaced either 25 % or 50 % of the ATH in the conventional coating by dry weight and was obtained from milled basement waste. FIG. 4B shows the thickness of impregnated ceiling facers produced from a coating composition comprising glass-based filler, where the glass-based filler replaced either 25 % or 50 % of the ATH in the conventional coating by dry weight and was obtained from milled CSM waste. The facers described by both FIG. 4A and FIG. 4B show slight differences or no differences in thickness compared to facers with conventional filler. For example, some of the facers with glass-based filler obtained from basement waste replacing 50 % by dry weight of the conventional ATH filler showed an increased thickness of about 0.04mm. Nevertheless, most of the facers with glass-based filler obtained from basement waste replacing 25 % by dry weight of the conventional filler show comparable thickness to conventional facers, and facers with glass-based filler obtained from CSM waste replacing 25 % and 50 % by dry weight of conventional filler also show comparable thicknesses to facers with conventional filler.

[0135] While light reflection, opacity, and porosity are critical to ceiling facers, porosity and water absorbency are of particular concern in facers used in gypsum boards. The coating applied to facers to form gypsum boards serves two main functions. First, during formation of an exemplary gypsum board, a liquid gypsum slurry is applied to a facer to adhere it to a gypsum core, therefore the facer needs be able to prevent the slurry from bleeding through to the opposite surface of the mat from which the slurry was applied. The coating (and the filler therein) decreases the porosity of the mat, preventing and / or reducing this bleed through. Furthermore, when gypsum boards are used as exterior sheathing in construction applications, ultimately to be covered with facade, they are exposed to the external environment and must be strong enough to survive exterior weathering for a period of time during construction. Waterabsorbency, measured by Cobb value, is important for the same reason, as well as for the final end application of the gypsum board which needs to have a low water uptake.

[0136] Another critical property of gypsum facers, Cobb value (g / m2), is a measure of the amount of water absorbed by a facer when the facer is subjected to a 100 mL column of water. Cobb value as described herein was measured using EN 520 for 2 hours. FIG. 5 shows the Cobb values and mean Cobb values of gypsum facers produced from a coating composition comprising glass-based filler, where the glass-based filler replaced either 25 % or 50 % of the CaCCh in the conventional coating by dry weight and was obtained from milled basement waste. As FIG. 5 demonstrates, the Cobb values of the gypsum facers comprising glass-based filler obtained from basement waste are extremely similar to those of gypsum facers with conventional fillers.

[0137] FIG. 6 A shows the thickness of gypsum facers produced from a coating composition comprising glass-based filler, where the glass-based filler replaced either 25 % or 50 % of the CaCCh in the conventional coating by dry weight and was obtained from milled basement waste. FIG. 6B shows the thickness of gypsum facers produced from a coating composition comprising glass-based filler, where the glass-based filler replaced either 25 % or 50 % of the CaCCh in the conventional coating by dry weight and was obtained from milled CSM waste. Thickness was measured by was measured by a Thwing- Albert testing machine, using ISO534. The thickness of the gypsum facers with glass-based filler obtained from basement waste and from CSM waste varied less than the thickness of conventional-filler based gypsum facers.

[0138] Tensile strength was measured using ISO1924 / 2 and is shown in FIG. 7A and FIG. 7B. FIG. 7 A shows the tensile strength of gypsum facers produced from a coating composition comprising glass-based filler, where the glass-based filler replaced either 25 % or 50 % of the CaCCh in the conventional coating by dry weight and was obtained from milled basement waste. FIG. 7B shows the tensile strength of gypsum facers produced from a coating composition comprising glass-based filler, where the glass-based filler replaced either 25 % or 50 % of the CaCCh in the conventional coating by dry weight and was obtained from milled CSM waste. The tensile strengths of the gypsum facers with glass-based filler (obtained from basement waste or CSM waste) hardly differ from the tensile strengths of gypsum facers with conventional filler.

[0139] Overall, it was surprisingly found that the glass filler obtained from both aforementioned sources of recycled glass resulted in impregnated ceiling facers having processable and commercially acceptable properties, such as porosity, opacity, and thickness. It was also surprisingly discovered that the glass filler obtained from both sources of recycled glass produced coated gypsum facers having little deviation in tensile strength compared to gypsum facers with conventional filler. Additionally, glass-based filler sourced from basement waste overall produced gypsum facers having processable and commercially acceptable properties to conventional facers such as Cobb value and wet tensile strength.Example 2

[0140] Milled recycled glass fabrics were also used as a filler in nonwoven mats. Compared to milled glass waste made from glass fibers or continuous fibers, glass fabrics contain a relatively high amount of organic material. When the inorganic filler is at least partially replaced in such glass fabrics, the fire retardancy may be deteriorated by the exchange.

[0141] In order to determine the impact of the use of milled recycled glass fabrics as filler on the fire retardancy of the nonwoven, glass nonwoven samples (Samples 1 and 2) were prepared in which 25 wt.% or 50 wt.% of the CaCCh filler in the coating formulation was replaced with milled glass fabric waste. In Comparative 1, the CaCCh filler is present in an amount of 95 wt.% of the coating composition. Each of the samples was tested for fire retardancy in accordance with ISO11925-2, Reaction to Fire - Ignitability of building products subjected to direct impingement of flame - Part 2: Single-flame source test. In particular, each of the nonwovens was exposed at the surface in the machine direction to the fire for 15 seconds. The results are provided in Table 3 below. In Table 3, the amounts of CaCCh and milled glass fabric waste are reported in wt.% based on a total weight of the coating composition.Table 3

[0142] As shown in Table 3, although all three nonwovens were self-extinguishable, the fire propagation decreased with increasing replacement of the CaCCh, which was unexpected because of the higher organic content in the milled glass fabric waste. However, it was noted that replacing CaCCE with milled glass fabric waste could reduce or eliminate the need to incorporate an additional fire retardant into the coating formulation.Example 3

[0143] Given the unexpected fire retardancy observed in Example 2, the use of milled glass fabric waste to replace alumina trihydrate (ATH) as a flame retardant in a nonwoven coating formulation.

[0144] Recycled glass was milled to particles of approximately 18 pm and 8 pm, and used to replace 50% or 100% of the ATH in a coating formulation. The formulations are presented in Table 4 below, with the amounts of filler being presented in wt.% based on the total weight of the coating formulation. Each of the formulations was applied to a nonwoven base mat formed from a blend of glass fibers having an average diameter of 11 pm or 6.5 pm.Table 4

[0145] The formulations worked well for impregnating the nonwoven mat, except for Sample 6, which included a relatively high amount of larger particles. The formulation of Sample 6 had much more sedimentation and exhibited a filtration effect on the final nonwoven, which led to a dusty and crumbly appearance.

[0146] In an effort to improve the coating formulation of Sample 6, various modifications were attempted, including increasing the amount of water, increasing the viscosity (e.g., through the use of a pH sensitive thickener and increasing the pH of the formulation), and using an alternative base nonwoven. However, it was noted that neither increasing the amount of water in the coating formulation or increasing the viscosity was sufficient to overcome thefiltration effect. The application of the formulation to a nonwoven mat formed from glass fibers having a diameter of 11 pm (as compared to a blend of fibers) yielded improved results, giving a good appearance.

[0147] Because Sample 3 provided the best appearance compared to Comparative 2, additional testing was done on Sample 3. The results are presented in Table 5 below. Color and opacity were measured according to the CIE L*a*b* color scale. Air porosity was also measured for the mat impregnated with the formulations having an end weight of 180 g / m2.Table 5

[0148] The drop in L* value for Sample 3 as compared to Comparative 2 was statistically significant and observable by the naked eye, while the change in a* and b* values and opacity was not significant or observable by the naked eye.

[0149] Because the porosity of the mats depended linearly on the end weight, an end weight of 180 g / m2was used as a point of comparison for the mats. By adding milled glass, the porosity of the nonwoven mat increased from 450 L / m2 / s to 538 L / m2 / s.

[0150] When fire retardancy was tested for Comparative 2 and Sample 3, there was no observable difference.

[0151] In some embodiments, it may be possible to utilize the various inventive concepts in combination with one another. Additionally, any particular element recited as relating to a particularly disclosed embodiment should be interpreted as available for use with all disclosed embodiments, unless incorporation of the particular element would be contradictory to the express terms of the embodiment. The scope of the general inventive concepts presented herein are not intended to be limited to the particular exemplary embodiments shown and describedherein. From the disclosure given, those skilled in the art will not only understand the general inventive concepts and their attendant advantages but will also find apparent various changes and modifications thereto. For example, while the nonwoven mats described herein are formed from glass fibers, other types of fibrous insulation material (e.g., mineral wool) may also be suitable. Also, while the filler particles described herein comprise recycled and milled glass waste, other sources, sizes, and types of glass may also be suitable. It is sought, therefore, to cover all such changes and modifications as fall within the spirit and scope of the general inventive concepts, as described and / or claimed herein, and any equivalents thereof.

Claims

CLAIMS1. A coating composition comprising: a polymeric binder; and a filler, wherein said filler comprises: from 5 to 100% by weight of glass particles comprising milled glass fibers or milled glass fiber-containing products; and from 0 to 95% by weight of an inorganic mineral component.

2. The coating composition of claim 1, wherein the milled glass fibers or milled glass fiber-containing products have an LOI of from about 0.1 % to about 5 %.

3. The coating composition of claim 1 or claim 2, wherein the milled glass fibers or milled glass fiber-containing products further comprise polymeric fibers or natural fibers.

4. The coating composition of claim 1, wherein the polymeric binder is an aqueous emulsion or solution of (co)polymers comprising at least one of the following monomers: styrene; (meth)acrylic acid or ester; alkyl (meth)acrylic acid or ester such as butyl acrylate, ethyl acrylate, methyl methacrylate, ethylhexyl acrylate; vinyl esters such as vinyl acetate, vinyl versatate; styrene-butadiene; vinyl alcohol; urea formaldehyde; starch based monomers; and mixtures thereof.

5. The coating composition of claim 1, wherein, when present, the inorganic mineral component is selected from the group consisting of aluminum trihydrate, calcium carbonate, magnesium carbonate, talc, vermiculite, antimony oxide, titanium dioxide, aluminum oxide, a clay, or a combination of any two or more of these substances, preferably aluminum trihydrate or calcium carbonate.

6. The coating composition of claim 1, wherein the filler comprises: from 10 to 90% by weight of glass particles, preferably from 15 to 75%; and from 10 to 90% by weight of an inorganic mineral component, preferably from 25 to 85%.

7. The coating composition of claim 1, wherein the glass particles are milled glass fibers or milled glass fiber-containing products.

8. The coating composition of claim 7, wherein the milled glass fibers or milled glass fiber-containing products are milled scrap or waste from glass fiber manufacturing processes or from glass fiber-containing products manufacturing processes, such as scrap or wastes from composites manufacturing processes, or are milled end-of-life glass fiber-containing products such as composites products.

9. The coating composition of claim 8, wherein the milled glass fiber-containing products are milled end-of-life glass fiber-containing products such as composites products, preferably wind turbine blades.

10. The coating composition of claim 1, wherein the coating composition further comprises at least one of a flame retardant, hydrophobic agent, defoamer, thickener, or dispersing agent.

11. A nonwoven mat comprising a nonwoven precursor mat coated or impregnated by the coating composition as defined in any one of claims 1 to 10.

12. A nonwoven mat comprising: a nonwoven precursor mat; and a coating composition comprising: a polymeric binder; and a filler, wherein said filler comprises: from 5 to 100% by weight of glass particles comprising milled glass fibers or milled glass fiber-containing products; and from 0 to 95% by weight of an inorganic mineral component; wherein the coating composition coats or impregnates the nonwoven precursor mat.

13. The nonwoven mat according to claim 12, wherein the milled glass fibers or milled glass fiber-containing products have an LOI of from about 0.1 % to about 5 %.

14. A construction board comprising a nonwoven mat attached to a core, wherein the nonwoven mat is defined in claim 11 and the core is selected from the group consisting of a ceiling tile, gypsum board, building panel, insulation panel, and floorboard, preferably a gypsum board or a ceiling tile.

15. Use of glass particles to replace at least partially the inorganic mineral filler of a coating composition comprising a polymeric binder and an inorganic mineral filler, for coating or impregnating a nonwoven mat.

16. A process for producing a coating composition, comprising a step of mixing a polymeric binder with a filler, wherein said filler comprises an inorganic mineral component; and wherein said filler further comprises glass particles comprising milled glass fibers or milled glass fiber-containing products.

17. The process of claim 16, wherein, before the mixing step, a milling step is performed on glass fibers or glass fiber-containing products, such as scrap or wastes from glass fiber manufacturing processes or from glass fiber-containing products manufacturing processes, such as scrap or wastes from composites manufacturing processes, or on end-of-life glass fibercontaining products such as composites products to produce the glass particles, resulting in the glass particles being in the form of milled glass fibers or milled glass fiber-containing products.

18. The process of claim 17, wherein, before the milling step, the glass fibers, glass fibercontaining products or end-of-life glass fiber-containing products are subject to a cleaning step to remove the organic part attached to said glass fibers or glass fiber-containing product or end- of-life glass fiber-containing products, typically through a pyrolysis or solvolysis step.

19. A process for producing a coated or impregnated nonwoven mat comprising coating or impregnating a nonwoven precursor mat with a coating composition as defined in any one of claims 1 to 10.

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