An aqueous composition for coating a non-woven fibrous mat

Abstract

An aqueous composition for coating a non-woven fibrous mat comprises an aqueous hydrophobic binder, a hydrophobically modified cellulose, an inorganic filler, a dispersant, and water. The aqueous hydrophobic binder is a copolymer of: i) a monomer unit selected from vinyl versatate, an isomer of vinyl versatate, or a mixture thereof; and ii) at least one monomer unit selected from (meth)acrylic acid, or (methyl)acrylate. Coated non-woven fibrous mats, methods for manufacturing coated non-woven fibrous mats, and construction boards comprising the coated non-woven fibrous mat are also described herein.

Description

[0001] AN AQUEOUS COMPOSITION FOR COATING A NON-WOVEN FIBROUS MAT

[0002] Cross-Reference to Related Application

[0003] This application claims priority to and the benefit of European Patent Application No. 23198078.0, filed September 18, 2023, the entire disclosure of which is incorporated by reference herein.

[0004] Field

[0005] The present invention relates to an aqueous composition for coating a non-woven fibrous mat, a coated non-woven fibrous mat, a method for manufacturing a coated non-woven fibrous mat, and a construction board comprising the coated non-woven fibrous mat.

[0006] Background

[0007] Fibrous mats such as fiberglass mats, have been employed as facers in the manufacture of construction boards, such as gypsum and polyisocyanurate boards. Traditionally, facer materials have included, among others, non-woven fibrous mats, including non-woven fiberglass mats. Non-woven fiberglass facers may be used to prepare boards with specific properties such as increased dimensional stability in the presence of moisture, increased biological resistance, increased air permeability, and greater physical and mechanical properties, such as better strength and durability, compared to conventional boards faced with polyester, paper or other cellulosic facing materials.

[0008] Non-woven fiber mats generally comprise randomly matted glass fibers bonded together by a cured thermoset or dried thermoplastic polymeric binder. The processes for forming such mats are generally well known, including for example, the well-known wet-laid processing and dry- laid processing methods. In one exemplary wet-laid process for forming non-woven fiberglass mats, chopped glass fibers are provided to a conveying apparatus such as a conveyor by a storage container for conveyance to a mixing tank that may contain the white water (e.g., various surfactants, viscosity modifiers, defoaming agents, and / or other chemical agents) with agitation to disperse the fibers and form a chopped glass fiber slurry. The glass fiber slurry may be transferred to a head box where the slurry is deposited onto a conveying apparatus such as a moving screen or foraminous conveyor, and a substantial portion of the water from the slurry is removed to form a web (mat) of enmeshed fibers. The water may be removed from the web by a conventional vacuum or air suction system. A precursor binder may be incorporated into the white water. Alternatively, a precursor binder may be applied to the web of enmeshed fibers as described above by a suitable binder applicator, such as a spray applicator or a curtain coater.

[0009] Once the binder has been applied to the mat, the binder coated mat is passed through at least one drying oven to remove any remaining water and dry and / or cure the binder composition. The formed non-woven fiber mat that emerges from the oven is an assembly of randomly oriented, dispersed, individual glass fibers.

[0010] The non-woven fiber mats may then be coated or impregnated with a coating composition, and dried and / or cured, forming a facing material, to impart various properties to the facing and downstream construction board panel. For construction boards panels, and typically for gypsum boards, it is important to have a facer that allows the gypsum slurry to dry to form the gypsum board, while preventing bleed through of the gypsum slurry through the fibrous mats.

[0011] Without wishing to be bound by theory, fibrous mats for gypsum boards are required to have two properties:

[0012] • Air permeability - the fibrous mat must be both sufficiently air permeable (i.e. open) such that the gypsum slurry can suitably dry via the evaporation of water vapour from the gypsum slurry through the fibrous mat, and sufficiently air impermeable (i.e. closed) to prevent bleed through of the gypsum slurry; and

[0013] • Hydrophobicity - the fibrous mat must exhibit a suitable degree of hydrophobicity to prevent undesirable bleed through of the aqueous gypsum slurry through the fibrous mat, as well as to provide resistance to humid environments, notably when the gypsum construction boards are for exterior usage.

[0014] It is also desirable for facers for construction boards to adhere strongly to the gypsum core once dried.

[0015] Several techniques are known to coat non-woven fiber mats, for example, fountain, curtain, knife, bar, roll-to-roll or reverse roll coating techniques. Usually, the coating compositions used are complex compositions including more than ten different components to have the right processability in manufacturing the fibrous mat, and for the coated veil to reach the targeted performances in the application (air permeability, degree of hydrophobicity, and adhesion).

[0016] Indeed, it is particularly challenging to obtain a simple composition that meets both the processability requirements for the knife-over-roll coating technique, and that also allows the fibrous mat to have the desired performance properties of good adhesion to the gypsum, air permeability, and hydrophobicity.

[0017] It is an object of the present invention to overcome or mitigate at least some of the problems of the prior art.

[0018] Definitions

[0019] The point of attachment of a repeat unit, moiety, or substituent is represented by For example, -COOH is attached through the carbon atom.

[0020] The term “about” or “approximately” means an acceptable error for a particular value as determined by a person of ordinary skill in the art, which depends in part on how the value is measured or determined. The term “about” or “approximately” may mean within 1, 2, 3 or 4 standard deviations. The term “about” or “approximately” may mean within 30%, 25%, 20%, 15%, 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%, or 0.5% of a given value or range.

[0021] Unless otherwise specified, “a,” “an,” “the,” and “at least one” are used interchangeably. Furthermore, as used in the description of the application and the appended claims, the singular forms “a,” “an,” and “the” are inclusive of their plural forms, unless contradicted by the context surrounding such.

[0022] “Alkyl” refers to a straight-chain, branched, or cyclic saturated hydrocarbon group. The alkyl group may have from 5-20 carbon atoms, for example from 7-17 carbon atoms, such as 10-15 carbon atoms. The alkyl group may be unsubstituted. Alternatively, the alkyl group may be substituted. Unless otherwise specified, the alkyl group may be attached at any suitable carbon atom and, if substituted, may be substituted at any suitable atom. “Aryl” refers to an aromatic carbocylic group or aromatic heterocarbocyclic group. When the aryl group is an aromatic carbocylic group, the aryl group may have a single ring or multiple condensed rings. The aryl group can have from 5-20 carbon atoms, for example from 6-20 carbon atoms, such as 6-12 carbon atoms. The aryl group may be unsubstituted. Alternatively, the aryl group may be substituted. Unless otherwise specified, the aryl group may be attached to any suitable carbon atom and, if substituted, may be substituted at any suitable atom. Examples of aryl groups include, but are not limited to, phenyl, tolyl (o-, m-, or p-), naphthyl, anthracenyl, and the like.

[0023] When the aryl group is an aromatic heterocarbocyclic group, one or more (e.g. 1, 2, 3, or more) of the carbon atoms in an aromatic carbocylic group is independently substituted with a heteroatom provided aromaticity is maintained. An aromatic heterocarbocyclic group may also be known as a heteroaryl group. The heteroaryl group may have a single ring or multiple condensed rings. The or each heteroatom may be independently selected from the group consisting of nitrogen, oxygen, phosphorus, sulfur. The or each heteroatom may be selected from nitrogen. The heteroaryl group may have from 4-20 carbon atoms, for example from 5- 20 carbon atoms, such as from 5-15 carbon atoms. The heteroaryl group may be unsubstituted. Alternatively, the heteroaryl group may substituted. Unless otherwise specified, the heteroaryl group may be attached at any suitable atom and, if substituted, may be substituted at any suitable atom. Examples of heteroaryl groups include but are not limited to thienyl, furanyl, pyrrolyl, imidazolyl, pyrazolyl, thiazolyl, isothiazolyl, oxazolyl, isoxazolyl, triazolyl, thiadiazolyl, thiophenyl, oxadiazolyl, pyridinyl, pyrimidyl, benzoxazolyl, benzthiazolyl, benzimidazolyl, indolyl, quinolinyl, and the like.

[0024] The term “consisting” is closed and excludes additional, unrecited elements or method steps in the claimed invention.

[0025] The term “consisting essentially of’ is semi-closed and occupies a middle ground between “consisting” and “comprising”. “Consisting essentially of’ does not exclude additional, unrecited elements or method steps which do not materially affect the essential character! stic(s) of the claimed invention.

[0026] The term “comprising” is inclusive or open-ended and does not exclude additional, unrecited elements or method steps in the claimed invention. The term is synonymous with “including but not limited to”. The term “comprising” encompasses three alternatives, namely (i) “comprising”, (ii) “consisting”, and (iii) “consisting essentially of’.

[0027] “Halo”, “hal” or “halide” refers to -F, -Cl, -Br and -I, for example -Cl, -Br and -I.

[0028] The terms “mat”, “veil”, and “facer” are used interchangeably herein and refer to a bound web of fibers.

[0029] Viscosity is a function of the rate of shear. A decrease in the viscosity of a composition (for example, a paste) with increasing rate of shear is called “shear thinning”, and an increase in the viscosity of a composition (for example, a paste) is called “shear thickening”.

[0030] The term “substantially free” means that the selected composition contain less than a functional amount of the stated ingredient or component, typically less than about 0.1 wt%, such as less than about 0.05 wt%, for example, less than about 0.03 wt% of the total composition.

[0031] “Substituted” refers to a group in which one or more (e.g. 1, 2, 3, 4, or 5) hydrogen atoms are each independently replaced with substituents which may be the same or different. The substituent may be any group which does not adversely affect the aqueous composition of the invention, the coated non-woven mat of the invention, or the precursor mat. Examples of substituents include, but are not limited to, -Ra, -O-Ra, -NRaRb, -CN, -COORa, and - CONRaRb, preferably -Ra. Raand Rbare independently selected from the groups consisting of H, alkyl, and aryl, such as phenyl, tolyl (o-, m-, or p-), naphthyl, anthracenyl, methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, t-butyl, pentyl, cyclo-pentyl, hexyl, cyclo-hexyl and the like.

[0032] Brief Description of the Figures

[0033] Certain aspects of the embodiments described herein may be more clearly understood by reference to the drawings, which is intended to illustrate but not limit, the invention, and wherein:

[0034] Figure 1 shows a representative thixotropy curve for the aqueous composition of the present invention using the thixotropy test described in the Examples. Figure 2 shows a representative graph with average Cobb values for (a) the coated non-woven veil of the present invention, and (b) a comparative coated non-woven veil.

[0035] Figure 3 shows a representative graph with average dolly adhesion values for (a) the coated non-woven veil of the present invention when adhered to a gypsum core, and (b) a comparative coated non-woven veil when adhered to a gypsum core.

[0036] Figure 4 shows a representative flow curve for comparative aqueous compositions and an aqueous composition of the present invention using the flow curve test described in the Examples.

[0037] Description of the Invention

[0038] Aqueous Composition

[0039] In one aspect, the present invention provides an aqueous composition for bonding a non-woven fibrous mat, the composition comprising:

[0040] • an aqueous hydrophobic binder;

[0041] • a hydrophobically modified cellulose;

[0042] • an inorganic filler;

[0043] • a dispersant; and

[0044] • water; wherein the aqueous hydrophobic binder is a copolymer of: i) a monomer unit selected from vinyl versatate, an isomer of vinyl versatate, or a mixture thereof; and ii) at least one monomer unit selected from (meth)acrylic acid, or (methyl)acrylate, such as acrylate, methacrylate, methyl methacrylate, or a combination thereof.

[0045] While various components in the aqueous composition may be expressed as a range, the total wt% of the aqueous composition adds up to 100 wt%.

[0046] The aqueous hydrophobic binder is a copolymer of: i) a monomer unit selected from vinyl versatate, an isomer of vinyl versatate, or a mixture thereof; and ii) at least one monomer unit selected from (meth)acrylic acid, or (methyl)acrylate. Vinyl versatate, and its isomers, are hydrophobic. Without wishing to be bound by theory, it is believed the long chain alkyl group contributes to the hydrophobicity of the copolymer.

[0047] The monomer unit which is vinyl versatate (also known as vinyl neodecanoate) has the following structure:

[0048] Vinyl versatate comprises a branched alkyl chain, namely -(CH2)s-tBu. Isomers of vinyl versatate include other vinyl ester monomers having a -C9H19 alkyl group. The isomers of vinyl versatate include a vinyl ester monomer having a straight-chain -C9H19 alkyl group i.e. H2C=C(H)-O-C(O)-(CH2)8-CH3. The isomers of vinyl versatate include a vinyl ester monomer having a branched-chain -C9H19 alkyl group, such as H2C=C(H)-O-C(O)-C(CH3)(CH3)- (CH2)5-CH3, H2C=C(H)-O-C(O)-CH2-C(CH3)(CH3)-(CH2)4-CH3, H2C=C(H)-O-C(O)-(CH2)2- C(CH3)(CH3)-(CH2)3-CH3, H2C=C(H)-O-C(O)-(CH2)3-C(CH3)(CH3)-(CH2)2-CH3, and

[0049] H2C=C(H)-O-C(O)-(CH2)4-C(CH3)(CH3)-CH2-CH3.

[0050] The other monomer unit is selected from the group consisting of (meth)acrylic acid, and (methyl)acrylate. This monomer unit may be selected from the group consisting of acrylic acid, methacrylic acid, methyl methacrylic acid, acrylate, methacrylate, methyl methacrylate, and combinations thereof.

[0051] The aqueous hydrophobic binder may be stabilized with a surfactant, such as an anionic surfactant. Suitable emulsion stabilizers are known in the art, and are described below.

[0052] The wt% of the hydrophobic binder may be in the range of about 3 wt% to about 40 wt% of the total weight of the aqueous composition. The wt% of the hydrophobic binder may be in the range of about 5 wt% to about 30 wt% of the total weight of the aqueous composition. The wt% of the hydrophobic binder may be > about 5.5 wt% of the total weight of the aqueous composition. The wt% of the hydrophobic binder may be > about 6 wt% of the total weight of the aqueous composition. The wt% of the hydrophobic binder may be > about 6.5 wt% of the total weight of the aqueous composition. The wt% of the hydrophobic binder may be > about 7 wt% of the total weight of the aqueous composition. The wt% of the hydrophobic binder may be > about 8 wt% of the total weight of the aqueous composition. The wt% of the hydrophobic binder may be > about 8.5 wt% of the total weight of the aqueous composition. The wt% of the hydrophobic binder may be > about 9 wt% of the total weight of the aqueous composition.

[0053] The wt% of the hydrophobic binder may be < about 30 wt% of the total weight of the aqueous composition. The wt% of the hydrophobic binder may be < about 25 wt% of the total weight of the aqueous composition. The wt% of the hydrophobic binder may be < about 20 wt% of the total weight of the aqueous composition. The wt% of the hydrophobic binder may be < about 15 wt% of the total weight of the aqueous composition. The wt% of the hydrophobic binder may be < about 14 wt% of the total weight of the aqueous composition. The wt% of the hydrophobic binder may be < about 13 wt% of the total weight of the aqueous composition. The wt% of the hydrophobic binder may be < about 12 wt% of the total weight of the aqueous composition. The wt% of the hydrophobic binder may be < about 11 wt% of the total weight of the aqueous composition. The wt% of the hydrophobic binder may be < about 10 wt% of the total weight of the aqueous composition.

[0054] The wt% of the hydrophobic binder may be in the range of about 9 wt% to about 10 wt% of the total weight of the aqueous composition, such as about 9.55 wt%.

[0055] The hydrophobic binder may be an aqueous dispersion i.e. the copolymer may be dispersed in a medium which is water. The solid content of the binder in water may be in the range of about 20 wt% to about 70 wt% of the total weight of the aqueous composition. The solid content of the binder in water may be in the range of about 30 wt% to about 60 wt% of the total weight of the aqueous composition. The solid content of the binder in water may be > about 35 wt% of the total weight of the aqueous composition. The solid content of the binder in water may be > about 39 wt% of the total weight of the aqueous composition. The solid content of the binder in water may be > about 40 wt% of the total weight of the aqueous composition. The solid content of the binder in water may be > about 41 wt% of the total weight of the aqueous composition. The solid content of the binder in water may be > about 42 wt% of the total weight of the aqueous composition. The solid content of the binder in water may be > about 43 wt% of the total weight of the aqueous composition. The solid content of the binder in water may be < about 60 wt% of the total weight of the aqueous composition. The solid content of the binder in water may be < about 55 wt% of the total weight of the aqueous composition. The solid content of the binder in water may be < about 50 wt% of the total weight of the aqueous composition. The solid content of the binder in water may be < about 49 wt% of the total weight of the aqueous composition. The solid content of the binder in water may be < about 48 wt% of the total weight of the aqueous composition. The solid content of the binder in water may be < about 47 wt% of the total weight of the aqueous composition. The solid content of the binder in water may be < about 46 wt% of the total weight of the aqueous composition. The solid content of the binder in water may be < about 45 wt% of the total weight of the aqueous composition.

[0056] The solid content of the binder in water may be about 44 wt% of the total weight of the aqueous composition.

[0057] The aqueous composition comprises a hydrophobically modified cellulose. Ahydrophobically modified cellulose is a water-soluble or water-dispersible polymer, in which hydrophobic groups have been introduced to the macromolecular chain of conventional cellulose or conventional cellulose derivatives, such as hydroxyethyl cellulose. Without wishing to be bound by theory, the hydrophobically modified cellulose appears to act as an associative thickener. In this respect, the hydrophobic groups form dynamic interactions between the thickener and the other components in the composition. As a result, the thickeners increase the viscosity of the composition under low shear conditions due to the reversible network formed. Under higher shear conditions, however, the network breaks down and the viscosity of the composition reduces. The hydrophobically modified cellulose therefore exhibits thixotropic behaviour.

[0058] The hydrophobic group may be selected from Cs-20-alkyl chains, such as Cio-i5-alkyl chains. The hydrophobic group may be introduced into the cellulose, or cellulose derivative, by methods known in the art. For example, the cellulose, or cellulose derivative, may be reacted with a haloalkane, i.e. a Cs-2o-alkyl-Hal.

[0059] The hydrophobically modified cellulose may have a weight average molecular weight (Mw) in the range of about 500000 to about 1000000 g / mole as measured by gel permeation chromatography (GPC), for example about 600000 to about 950000 g / mole as measured by GPC, such as about 700000 to about 900000 g / mole as measured by GPC. A suitable method for determining the Mw by GPC is provided in the Examples.

[0060] The hydrophobically modified cellulose may be selected from the group consisting of hydrophobically modified hydroxymethylcellulose, hydrophobically modified hydroxyethylcellulose, hydrophobically modified hydroxypropylcellulose, hydrophobically modified methylhydroxyethylcellulose, hydrophobically modified methylhydroxypropylcellulose, or a combination thereof. The hydrophobically modified cellulose may be hydrophobically modified hydroxy ethylcellulose.

[0061] Any suitable quantity of hydrophobically modified cellulose may be used in the aqueous composition provided the aqueous composition has a high viscosity under low shear, and the aqueous composition is thixotropic under high shear i.e. the viscosity reduces when it comes into contact with the knife in the knife-over-roll coating technique.

[0062] The wt% of the hydrophobically modified cellulose may be in the range of about 0.05 wt% to about 1 wt% of the total weight of the aqueous composition. The wt% of the hydrophobically modified cellulose may be in the range of about 0.1 wt% to about 0.8 wt% of the total weight of the aqueous composition. The wt% of the hydrophobically modified cellulose may be > about 0.15 wt% of the total weight of the aqueous composition. The wt% of the hydrophobically modified cellulose may be > about 0.2 wt% of the total weight of the aqueous composition. The wt% of the hydrophobically modified cellulose may be > about 0.25 wt% of the total weight of the aqueous composition. The wt% of the hydrophobically modified cellulose may be > about 0.3 wt% of the total weight of the aqueous composition. The wt% of the hydrophobically modified cellulose may be > about 0.35 wt% of the total weight of the aqueous composition. The wt% of the hydrophobically modified cellulose may be > about 0.4 wt% of the total weight of the aqueous composition. The wt% of the hydrophobically modified cellulose may be > about 0.45 wt% of the total weight of the aqueous composition. The wt% of the hydrophobically modified cellulose may be > about 0.5 wt% of the total weight of the aqueous composition.

[0063] The wt% of the hydrophobically modified cellulose may be < about 0.8 wt% of the total weight of the aqueous composition. The wt% of the hydrophobically modified cellulose may be < about 0.75 wt% of the total weight of the aqueous composition. The wt% of the hydrophobically modified cellulose may be < about 0.7 wt% of the total weight of the aqueous composition. The wt% of the hydrophobically modified cellulose may be < about 0.65 wt% of the total weight of the aqueous composition. The wt% of the hydrophobically modified cellulose may be < about 0.6 wt% of the total weight of the aqueous composition.

[0064] The wt% of the hydrophobically modified cellulose may be in the range of about 0.5 wt% to about 0.6 wt% of the total weight of the aqueous composition, such as about 0.55 wt%.

[0065] The aqueous composition comprises an inorganic filler. A filler may also be referred to as a mineral pigment. Any suitable filler may be used. When the coated non-woven fibrous mat is for use in a gypsum board, it is usually desirable for the filler / mineral pigment to be white. Examples of fillers suitable for making coated mats include, but are not limited to calcium carbonate, magnesium carbonate, talc, aluminum trihydrate, vermiculite, antimony oxide, titanium dioxide, aluminium trihydrate (AI2O3), a clay, or a combination of any two or more of these substances. An example of suitable filler is calcium carbonate.

[0066] When the filler is calcium carbonate, the calcium carbonate can act as a buffer and the pH of the aqueous composition may be stabilised.

[0067] The amount of filler in the aqueous composition may be described as a percent weight of filler based on the total weight of the aqueous composition. Without wishing to be found by theory, fillers (for example, calcium carbonate) can bring opacity and a white appearance to a bonded fibrous non-woven mat.

[0068] The aqueous composition may comprise filler in a range of about 50 wt% to about 95 wt% total weight of the aqueous composition. The aqueous composition may comprise filler in an amount of > about 50 wt% total weight of the coating composition. The aqueous composition may comprise filler in an amount of > about 55 wt% total weight of the aqueous composition. The aqueous composition may comprise filler in an amount of > about 60 wt% total weight of the aqueous composition. The aqueous composition may comprise filler in an amount of > about 61 wt% total weight of the aqueous composition. The aqueous composition may comprise filler in an amount of > about 62 wt% total weight of the aqueous composition. The aqueous composition may comprise filler in an amount of > about 63 wt% total weight of the aqueous composition. The aqueous composition may comprise filler in an amount of > about 64 wt% total weight of the aqueous composition.

[0069] The aqueous composition may comprise filler in an amount of < about 95 wt% total weight of the aqueous composition. The aqueous composition may comprise filler in an amount of < about 90 wt% total weight of the aqueous composition. The aqueous composition may comprise filler in an amount of < about 85 wt% total weight of the aqueous composition. The aqueous composition may comprise filler in an amount of < about 80 wt% total weight of the aqueous composition. The aqueous composition may comprise filler in an amount of < about 75 wt% total weight of the aqueous composition. The aqueous composition may comprise filler in an amount of < about 70 wt% total weight of the aqueous composition. The aqueous composition may comprise filler in an amount of < about 69 wt% total weight of the aqueous composition. The aqueous composition may comprise filler in an amount of < about 68 wt% total weight of the aqueous composition. The aqueous composition may comprise filler in an amount of < about 67 wt% total weight of the aqueous composition. The aqueous composition may comprise filler in an amount of < about 66 wt% total weight of the aqueous composition.

[0070] The aqueous composition may comprise filler in a range of about 65 wt% to about 66 wt% total weight of the aqueous composition, such as about 65.2 wt%.

[0071] The aqueous composition comprises a dispersant. Suitable examples of dispersants include but are not limited to polyphosphate salts, polycarboxylate salts, poly(meth)acrylate salts, or citrate salts, for example, ammonium polyphosphate, sodium polyphosphate, ammonium polycarboxylate, sodium polycarboxylate, ammonium poly(meth)acrylate, sodium poly(meth)acrylate, ammonium citrate, or sodium citrate. The dispersant may be sodium polyphosphate.

[0072] The wt% of the dispersant may be in the range of about 0.05 wt% to about 1 wt% of the total weight of the aqueous composition. The wt% of the dispersant may be in the range of about 0.1 wt% to about 0.8 wt% of the total weight of the aqueous composition.

[0073] The wt% of the dispersant may be > about 0.05 wt% of the total weight of the aqueous composition. The wt% of the dispersant may be > about 0.06 wt% of the total weight of the aqueous composition. The wt% of the dispersant may be > about 0.07 wt% of the total weight of the aqueous composition. The wt% of the dispersant may be > about 0.08 wt% of the total weight of the aqueous composition. The wt% of the dispersant may be > about 0.09 wt% of the total weight of the aqueous composition. The wt% of the dispersant may be > about 1 wt% of the total weight of the aqueous composition. The wt% of the dispersant may be > about 0.11 wt% of the total weight of the aqueous composition. The wt% of the dispersant may be > about 0.12 wt% of the total weight of the aqueous composition.

[0074] The wt% of the dispersant may be < about 0.8 wt% of the total weight of the aqueous composition. The wt% of the dispersant may be < about 0.7 wt% of the total weight of the aqueous composition. The wt% of the dispersant may be < about 0.6 wt% of the total weight of the aqueous composition. The wt% of the dispersant may be < about 0.5 wt% of the total weight of the aqueous composition. The wt% of the dispersant may be < about 0.45 wt% of the total weight of the aqueous composition. The wt% of the dispersant may be < about 0.4 wt% of the total weight of the aqueous composition. The wt% of the dispersant may be < about 0.35 wt% of the total weight of the aqueous composition. The wt% of the dispersant may be < about 0.3 wt% of the total weight of the aqueous composition. The wt% of the dispersant may be < about 0.25 wt% of the total weight of the aqueous composition. The wt% of the dispersant may be < about 0.2 wt% of the total weight of the aqueous composition. The wt% of the dispersant may be < about 0.15 wt% of the total weight of the aqueous composition.

[0075] The wt% of the dispersant may be in the range of about 0.12 wt% to about 0.15 wt% of the total weight of the aqueous composition, such as about 0.13 wt%.

[0076] The composition of the invention is aqueous i.e. contains water. The quantity of water in the composition is not particularly limited provided the viscosity of the composition is not so high to inhibit deposition of the aqueous on the precursor mat, or so low so that the composition is too runny to adequately coat the precursor mat.

[0077] The aqueous composition may comprise water in a range of about 10 wt% to about 50 wt% total weight of the aqueous composition. The aqueous composition may comprise water in an amount of > about 10 wt% total weight of the aqueous composition. The aqueous composition may comprise water in an amount of > about 15 wt% total weight of the aqueous composition. The aqueous composition may comprise water in an amount of > about 20 wt% total weight of the aqueous composition. The aqueous composition may comprise water in an amount of > about 21 wt% total weight of the aqueous composition. The aqueous composition may comprise water in an amount of > about 22 wt% total weight of the aqueous composition. The aqueous composition may comprise water in an amount of > about 23 wt% total weight of the aqueous composition. The aqueous composition may comprise water in an amount of > about 24 wt% total weight of the aqueous composition.

[0078] The aqueous composition may comprise water in an amount of < about 50 wt% total weight of the aqueous composition. The aqueous composition may comprise water in an amount of < about 45 wt% total weight of the aqueous composition. The aqueous composition may comprise water in an amount of < about 35 wt% total weight of the aqueous composition. The aqueous composition may comprise water in an amount of < about 30 wt% total weight of the aqueous composition. The aqueous composition may comprise water in an amount of < about 29 wt% total weight of the aqueous composition. The aqueous composition may comprise water in an amount of < about 28 wt% total weight of the aqueous composition. The aqueous composition may comprise water in an amount of < about 27 wt% total weight of the aqueous composition. The aqueous composition may comprise water in an amount of < about 26 wt% total weight of the aqueous composition. The aqueous composition may comprise water in an amount of < about 25 wt% total weight of the aqueous composition.

[0079] The aqueous composition may comprise water in a range of about 24 wt% to about 25 wt% total weight of the aqueous composition, such as about 24.57 wt%.

[0080] The quantity of water present in the aqueous hydrophobic binder or pH adjuster (if a pH adjuster is used and if the pH adjuster contains water) may be taken into account if desired when calculating the quantity of water to be used.

[0081] The aqueous composition is thixotropic and exhibits a shear thinning behavior. A suitable method for determining the thixotropy of the aqueous composition is the thixotropy test as provided in the Examples. A suitable method for determining the shear thinning behavior can be determined with a flow curve test as provided in the Examples. Both tests may be carried out at a temperature of about 25 °C.

[0082] The aqueous composition of the present invention has three viscosity properties which make it suitable for use in a knife-over-roll technique. Firstly, the aqueous composition has a suitably high viscosity under low shear to avoid the aqueous composition being too fluid. As such, the aqueous composition does not undesirably bleed through the non-woven fibrous mat. The inventors have found that a minimum viscosity under low shear of 2 x 106mPa.s at a temperature of about 25 °C and a shear rate of about 0.01 s'1is typically desirable.

[0083] Secondly, the aqueous composition undergoes shear thinning on contact with the knife in the knife-over-roll technique and has a suitably low viscosity such that non-woven fibrous mat is suitably coated but bleed through of the non-woven fibrous mat still does not occur.

[0084] Thirdly, after contact with the knife in the knife-over-roll technique has ceased, the aqueous composition increases to a suitably high viscosity (under low shear conditions) to once again prevent the aqueous composition undesirably bleeding though the non-woven fibrous mat.

[0085] The change in viscosity of the aqueous composition from a suitably high viscosity (under low shear and before contact with the knife) to a suitably low viscosity (under high viscosity during contact with the knife) to a suitably high viscosity (under low shear and after contact with the knife) forms the asymmetric coated non-woven veil of the present invention.

[0086] As measured by the flow curve test described herein, the aqueous composition may have a viscosity in the range of about 2 x 106mPa.s to about 3 x 107mPa.s (such as about 5 x 106mPa.s to about 1.2 x 107mPa.s) at a temperature of about 25 °C and a shear rate of 0.01 s’1, and a viscosity in the range of about 300 mPa.s to about 1200 mPa.s (such as about 400 mPa.s to about 1000 mPa.s) at a temperature of about 25 °C and a shear rate of 1000 s’1.

[0087] Alternatively or in addition, as determined by the thixotropy test described herein, the aqueous composition may have a viscosity in the range of about 2 x 106mPa.s to about 3 x 107mPa.s (such as about 8 x 106mPa.s to about 1.2 x 107mPa.s) at a temperature of about 25 °C and a shear rate of 0.01 s’1. In this instance, the viscosity reduces to a viscosity in the range of about 300 mPa.s to about 1200 mPa.s (such as about 400 mPa.s to about 1000 mPa.s) when the aqueous composition is exposed to a shear rate of 1000 s’1for 30 seconds. Then, for the thixotropic behaviour to be confirmed, after the high shear exposure has ceased and after a period of about 10 seconds has lapsed, the viscosity of the aqueous composition increases once again to a range of about 1 x 105mPa.s and about 4 x 105mPa.s (such as about 1.5 x 105mPa.s to about 2.5 x 105mPa.s). Alternatively or in addition, the Viscometer viscosity of the aqueous composition may be in the range of about 10000 mPa.s to about 150000 mPa.s (about 10000 cP to about 150000 cP), such as about 12000 mPa.s to about 120000 mPa.s (about 12000 cP to about 120000 cP) at a temperature of about 25 °C using a suitable method for determining Viscometer viscosity of the aqueous composition as provided in the Examples. As noted above, it is important to ensure the compatibility of the aqueous composition with the knife over-roll coating technique. The inventors have found that a viscometer viscosity that is below a minimum of about 10000 mPa. s (about 10000 cP) is typically undesirable as the aqueous composition would be too fluid and would bleed through the non-woven fibrous mat.

[0088] The aqueous composition may have an alkaline pH. The pH may be any suitable alkaline pH provided it does not adversely affect the composition, any component in the composition, the precursor mat, or the coated non-woven fibrous mat. The pH of the aqueous composition may be > about 8 and < about 12.

[0089] The aqueous composition may include a pH adjuster. The aqueous composition may include about 0.01% to about 0.5%, for example from about 0.05% to about 0.4%, such as from about 0.1% to about 0.3% pH adjuster based on the total weight of the aqueous composition. The pH adjuster may be selected from one or more (e.g. 1, 2, 3, 4, 5, or more) inorganic bases. Alternatively or in addition, the pH adjuster may be selected from one or more (e.g. 1, 2, 3, 4, 5, or more) organic bases. When the pH of the aqueous composition needs to made alkaline or more alkaline, suitable examples of pH adjusters include but are not limited to calcium hydroxide, sodium hydroxide, potassium hydroxide, 30% aqueous ammonia, aminomethyl propanol (e.g. 2-amino-2-methyl-l -propanol), 2-dimethylamino ethanol, di ethanol amine, 3- dimethylamino-1 -propanol, or N-methylethanolamine. When the pH of the aqueous composition is too high and needs to be made less alkaline, suitable examples of pH adjusters include acids, such as citric acid, acetic acid, oxalic acid, and lactic acid.

[0090] The aqueous composition may further comprise an additive selected from the group consisting of a biocide, defoamer, pigment, preservative, emulsion stabilizer, wetting and levelling agent, cross-linker, and combinations thereof. The aqueous composition may optionally include a biocide. The fouling of non-woven mats and facers primarily occurs through accumulated charged particles, biological growth, and fungal growth. Biological or fungal attacks are more typically a problem in pools, showers, and other hot, humid environments, but can also occur in any surface covering or dry wall application. Examples of suitable biocides include but are not limited to diiodomethyl-p- tolylsulfone, glutarealdehyde, isothiazolin, isothiazolin derivatives, zinc oxide, zinc omadine, sodium omadine, and silver, such as sodium omadine. To prevent discoloration or unwanted microbiological or fungal attack, biocides, such as antimicrobial and / or antifungal agents may be present in coated non-woven fibrous mat. The aqueous composition may include about 0.00001% to about 0.15% biocide based on the total weight of the aqueous composition i.e. the total weight of the aqueous hydrophobic binder, the filler, the dispersant, the thickener, water, biocide, and one or more further additives (if present). The aqueous composition may include about 0.0001% to about 0.015% biocide, such as about 0.0005% to about 0.001% biocide, based on the total weight of the aqueous composition i.e. the total weight of the aqueous hydrophobic binder, the filler, the dispersant, the thickener, water, biocide, and one or more further additives (if present). The aqueous composition may include about 0.0015% biocide, based on the total weight of the aqueous composition i.e. the total weight of the aqueous hydrophobic binder, the filler, the dispersant, the thickener, water, biocide, and one or more further additives (if present).

[0091] The aqueous composition may optionally include a pigment. For the purposes of the invention, pigments can be both inorganic and organic in nature. Suitable pigments are known to the person skilled in the art. They are regularly offered in comminuted form, for example as primary particles or as pigment agglomerates. Examples of suitable pigments include but are not limited to iron oxides, copper carbonates, copper hydroxychlorides, copper calcium silicates, cobalt aluminate blue, ultramarine blue, azo pigments, titanium dioxide, zinc sulphide and any desired mixtures thereof. The aqueous composition may include about 0.01% to about 3%, for example from about 0.1% to about 2%, such as from about 0.5% to about 1.5% pigment based on the total weight of the aqueous composition. Suitable examples of pigments include but are not limited to white, and blue pigments.

[0092] The aqueous composition may consist essentially of:

[0093] • an aqueous hydrophobic binder; • a hydrophobically modified cellulose;

[0094] • an inorganic filler;

[0095] • a dispersant;

[0096] • a biocide;

[0097] • water; and

[0098] • optionally, a pigment; wherein the aqueous hydrophobic binder is a copolymer of i) a monomer unit selected from vinyl versatate, an isomer of vinyl versatate, or a mixture thereof; and ii) at least one monomer unit selected from (meth)acrylic acid, or (methyl)acrylate.

[0099] The aqueous composition may consist of

[0100] • an aqueous hydrophobic binder;

[0101] • a hydrophobically modified cellulose;

[0102] • an inorganic filler;

[0103] • a dispersant;

[0104] • a biocide;

[0105] • water; and

[0106] • optionally, a pigment; wherein the aqueous hydrophobic binder is a copolymer of i) a monomer unit selected from vinyl versatate, an isomer of vinyl versatate, or a mixture thereof; and ii) at least one monomer unit selected from (meth)acrylic acid, or (methyl)acrylate.

[0107] The aqueous composition may optionally include a defoaming agent. A defoaming agent is also known as an anti-foam agent. The aqueous composition may include about 0.001% to about 0.05%, for example from about 0.002% to about 0.05%, such as from about 0.008% to about 0.02% defoaming agent based on the total weight of the aqueous solution. Suitable examples of defoaming agents include but are not limited to siloxanes, mineral oil, and polyoxalkylene, modified fatty and alkoxylated compounds, silica, emulsifiers, or a combination thereof. The defoaming (or anti-foam) agent may be a blend of modified fatty and alkoxylated compounds, silica and emulsifiers, stabilised with nonionic surfactant. Alternatively, the aqueous composition does not include a defoaming agent.

[0108] The aqueous composition may include an emulsion stabilizer. The aqueous composition may include about 0.01% to about 0.5%, for example from about 0.05% to about 0.4%, such as from about 0.1% to about 0.3% emulsion stabilizer based on the total weight of the aqueous composition. Suitable examples of emulsion stabilizers include but are not limited to bentonite clay, nonionic octylphenol ethoxylate surfactant, tall oil resin and natural resin extract.

[0109] Alternatively, the aqueous composition does not include an emulsion stabilizer.

[0110] The aqueous composition may include a wetting and levelling agent. The aqueous composition may include about 0.01% to about 0.5%, for example from about 0.05% to about 0.4%, such as from about 0.1% to about 0.3% wetting and levelling agent based on the total weight of the aqueous composition. Suitable examples of wetting and levelling agents include but are not limited to sulfosuccinate, polyether modified siloxane, urea modified polyurethane, modified urea ammonium salt of an acrylate copolymer.

[0111] Alternatively, the aqueous composition does not include a wetting and levelling agent.

[0112] The aqueous composition may include a cross-linker. The aqueous composition may include about 0.01% to about 0.5%, for example from about 0.05% to about 0.4%, such as from about 0.1% to about 0.3% cross-linker based on the total weight of the aqueous composition. Suitable examples of cross-linkers include but are not limited to zinc oxide, zinc metal ions, stabilized ammonium zirconium carbonate containing anionic hydroxylated zirconium polymers and epoxy functional silane.

[0113] Alternatively, the aqueous composition does not include a cross-linker.

[0114] Coated Non-Woven Fibrous Mat

[0115] In one aspect, the present invention relates to a coated non-woven fibrous mat, the coated nonwoven fibrous mat comprising:

[0116] (a) a precursor mat comprising:

[0117] • a non-woven web of fibers comprising glass fibers, and a first binder; and

[0118] (b) a hydrophobic coating which coats the precursor mat, wherein the hydrophobic coating is formed from the aqueous composition as described herein.

[0119] The precursor mat is coated with the aqueous composition as described herein. Once dried, the coating is hydrophobic.

[0120] The coated non-woven fibrous mat is asymmetric. By “asymmetric”, we mean that the aqueous composition of the present invention does not completely impregnate the precursor mat. Instead, the aqueous composition coats or sits solely on one side of the precursor mat. In this respect, the aqueous composition will be detectable on coated side of the precursor mat but will not be detectable on the other (uncoated) side of the mat.

[0121] The coated non-woven fibrous mat comprises a precursor mat. The precursor mat comprises (a) a non-woven web of fibers comprising glass fibers, and (b) a first binder, or combination thereof.

[0122] A non-woven web of fibers means that the glass fibers are randomly orientated.

[0123] The glass fibers may be formed by conventional methods known to those skilled in the art. In this respect, the glass fibers may be formed by a continuous manufacturing process in which molten glass passes through the holes of a bushing, the streams of molten glass thereby formed are solidified into filaments, and the filaments are combined together to form a fiber, “roving,” “strand,” or the like.

[0124] After the glass fibers are drawn from the bushing, an aqueous sizing composition (also referred to as a size) may optionally be applied to the fibers. The sizing composition is not limited, and may be any sizing composition known to those of skill in the art. Generally sizing compositions contain a lubricant to protect the fibers from damage by abrasion. The sizing composition may be applied by conventional methods such as by an application roller or by spraying the size directly onto the fibers. The size protects the glass fibers from breakage during subsequent processing, helps to retard interfilament abrasion, ensures the integrity of the strands of glass fibers, promotes the interconnection of the glass filaments that form the strand, etc. After the glass fibers are treated with the sizing composition, they may be chopped for subsequent processing into a wet-laid, non-woven mat as described below. The chopped fibers may have varying lengths from each other within the non-woven mat.

[0125] The glass fibers may have a mean fiber diameter as described below and a mean fiber length as described below.

[0126] The glass fibers may have a mean fiber diameter in the range of > about 5 pm and < about 20 pm. The glass fibers may have a mean fiber diameter in the range of > about 8 pm and < about 17 pm. The glass fibers may have a mean fiber diameter in the range of > about 10 pm and < about 15 pm.

[0127] The glass fibers may have a mean fiber diameter of > about 8 pm. The glass fibers may have a mean fiber diameter of > about 8.5 pm. The glass fibers may have a mean fiber diameter of > about 9 pm. The glass fibers may have a mean fiber diameter of > about 9.5 pm. The glass fibers may have a mean fiber diameter of > about 10 pm. The glass fibers may have a mean fiber diameter of > about 10.5 pm. The glass fibers may have a mean fiber diameter of > about 11 pm. The glass fibers may have a mean fiber diameter of > about 11.5 pm. The glass fibers may have a mean fiber diameter of > about 12 pm. The glass fibers may have a mean fiber diameter of > about 12.5 pm.

[0128] The glass fibers may have a mean fiber diameter of < about 17 pm. The glass fibers may have a mean fiber diameter < about 16.5 pm. The glass fibers may have a mean fiber diameter of < about 16 pm. The glass fibers may have a mean fiber diameter of < about 15.5 pm. The glass fibers may have a mean fiber diameter of < about 15 pm. The glass fibers may have a mean fiber diameter of < about 14.5 pm. The glass fibers may have a mean fiber diameter of < about 14 pm. The glass fibers may have a mean fiber diameter of < about 13.5 pm.

[0129] The glass fibers may have a mean fiber diameter of about 13 pm.

[0130] The glass fibers may have a mean fiber length in the range of > about 8 mm and < about 30 mm. The glass fibers may have a mean fiber length in the range of > about 10 mm and < about 28 mm. The glass fibers may have a mean fiber length in the range of > about 12 mm and < about 26 mm. The glass fibers may have a mean fiber length in the range of > about 14 mm and < about 24 mm.

[0131] The glass fibers may have a mean fiber length of > about 14.5 mm. The glass fibers may have a mean fiber length of > about 15 mm. The glass fibers may have a mean fiber length of > about 15.5 mm. The glass fibers may have a mean fiber length of > about 16 mm. The glass fibers may have a mean fiber length of > about 16.5 mm. The glass fibers may have a mean fiber length of > about 17 mm. The glass fibers may have a mean fiber length of > about 17.5 mm. The glass fibers may have a mean fiber length of > about 18 mm. The glass fibers may have a mean fiber length of > about 18.5 mm.

[0132] The glass fibers may have a mean fiber length < about 23.5 mm. The glass fibers may have a mean fiber length of < about 23 mm. The glass fibers may have a mean fiber length of < about 22.5 mm. The glass fibers may have a mean fiber length of < about 22 mm. The glass fibers may have a mean fiber length of < about 21.5 mm. The glass fibers may have a mean fiber length of < about 21 mm. The glass fibers may have a mean fiber length of < about 20.5 mm. The glass fibers may have a mean fiber length of < about 20mm. The glass fibers may have a mean fiber length of < about 19.5 mm.

[0133] The glass fibers may have a mean fiber length of about 19 mm.

[0134] The glass fibers may comprise SiCh in a range from about 50 to about 65 wt% of the total wt% of the glass composition. The glass fibers may comprise SiCh in a range from about 51 to about 62 wt% of the total wt% of the glass composition. The glass fibers may comprise SiCh in a range from about 52 to about 62 wt% of the total wt% of the glass composition, such as about 52 to about 56 wt% of the total wt% of the glass composition or about 55 wt% to about 60.4 wt% of the total wt% of the glass composition. The glass fibers may comprise SiCh in a range from about 54 to about 62 wt% of the total wt% of the glass composition. The glass fibers may comprise SiCh in about 58 wt% of the total wt% of the glass composition. The glass fibers may comprise SiCh in about 59 wt% of the total wt% of the glass composition. The glass fibers may comprise SiCh in about 60 wt% of the total wt% of the glass composition, such as about 60.1 wt%. The glass fibers may comprise AI2O3 in a range from about 7 to about 25 wt% of the total wt% of the glass composition. The glass fibers may comprise AI2O3 in a range from about 7 to about 20 wt% of the total wt% of the glass composition. The glass fibers may comprise AI2O3 in a range from about 19 to about 25 wt% of the total wt% of the glass composition. The glass fibers may comprise AI2O3 in a range from about 9 to about 15 wt% of the total wt% of the glass composition. The glass fibers may comprise AI2O3 in a range from about 12 to about 16 wt% of the total wt% of the glass composition, such as about 12 to about 15 wt% of the total wt% of the glass composition. The glass fibers may comprise AI2O3 in a range from about 17 to about 20 wt% of the total wt% of the glass composition. The glass fibers may comprise AI2O3 in about 11.5 wt% of the total wt% of the glass composition, such as about 11.6 wt%. The glass fibers may comprise AI2O3 in about 12 wt% of the total wt% of the glass composition, such as about 12.1 wt%. The glass fibers may comprise AI2O3 in about 13 wt% of the total wt% of the glass composition, such as about 13.2 wt%.

[0135] The glass fibers may contain B2O3 i.e. the glass fibers are boron-containing glass fibers. The glass fibers may comprise B2O3 in a range from about 1 wt% to about 12 wt% of the total wt% of the glass composition. The glass fibers may comprise B2O3 in a range from about 4 to about 6 wt% of the total wt% of the glass composition. The glass fibers may comprise B2O3 in a range from about 5 to about 10 wt% of the total wt% of the glass composition. The glass fibers may comprise B2O3 in a range from about 7 to about 12 wt% of the total wt% of the glass composition. Without wishing to be bound by theory, boron-containing glass fibers typically have lower softening points than boron-free glass fibers. The process for preparing the fibers typically utilise less energy than the boron-free fibers (because the glass melt typically has a lower softening point). The lower softening point of the boron-containing glass fibers may be of use in the application of the fibers.

[0136] The glass fibers may comprise substantially no B2O3 i.e. the glass fibers may be substantially boron-free fibers. The glass fibers may contain less than 0.2 wt% B2O3 of the total wt% of the glass composition. The glass fibers may comprise no B2O3 i.e. the glass fibers may be boron- free fibers. Without wishing to be bound by theory, boron-free or substantially boron-free glass fibers are more environmentally friendly than the boron-containing glass fibers as melts from which the fibers are made do not emit boron into the environment during processing. The fibers themselves typically have higher softening points than boron-containing fibers which may be of use in the application of the fibers. The glass fibers may comprise CaO in a range from about 7 to about 30 wt% of the total wt% of the glass composition. The glass fibers may comprise CaO in a range from about 7 to about 12 wt% of the total wt% of the glass composition. The glass fibers may comprise CaO in a range from about 12 to about 30 wt% of the total wt% of the glass composition. The glass fibers may comprise CaO in a range from about 16 to about 25 wt% of the total wt% of the glass composition, such as about 17 to about 25 wt% of total wt% of the glass composition. The glass fibers may comprise CaO in a range from about 21 to about 23 wt% of the total wt% of the glass composition. The glass fibers may comprise CaO in a range from about 24 to about 30 wt% of the total wt% of the glass composition. The glass fibers may comprise CaO in about 21.7 wt% of the total wt% of the glass composition. The glass fibers may comprise CaO in about 22 wt% of the total wt% of the glass composition. The glass fibers may comprise CaO in about 22.1 wt% of the total wt% of the glass composition. The glass fibers may comprise CaO in about 22.6 wt% of the total wt% of the glass composition.

[0137] The glass fibers may comprise MgO in a range from about 0.1 to about 15 wt% of the total wt% of the glass composition. The glass fibers may comprise MgO in a range from about 0.1 to about 8 wt% of the total wt% of the glass composition, such as about 0.1 to about 4 wt% of the total wt% of the glass composition. The glass fibers may comprise MgO in a range from about 8 to about 15 wt% of the total wt% of the glass composition. The glass fibers may comprise MgO in a range from about 0.1 to about 5 wt% of the total wt% of the glass composition. The glass fibers may comprise MgO in a range from about 0.4 to about 4 wt% of the total wt% of the glass composition. The glass fibers may comprise MgO in about 2 wt% of the total wt% of the glass composition. The glass fibers may comprise MgO in about 3.1 wt% of the total wt% of the glass composition. The glass fibers may comprise MgO in about 3.4 wt% of the total wt% of the glass composition.

[0138] The glass fibers may comprise substantially no MgO i.e. the glass fibers may be substantially magnesium-free fibers. The glass fibers may comprise no MgO i.e. the glass fibers may be magnesium-free fibers.

[0139] The glass fibers may comprise ZnO in a range from about 0.1 to about 4 wt% of the total wt% of the glass composition. The glass fibers may comprise ZnO in a range from about 0.5 to about 1 wt% of the total wt% of the glass composition, such as about 1 wt%. The glass fibers may comprise ZnO in a range from about 2 to about 5 wt% of the total wt% of the glass composition. The glass fibers may comprise ZnO in a range from about 1 to about 4 wt% of the total wt% of the glass composition, such as about 1.1 to about 3 wt%. The glass fibers may comprise ZnO in about 2.9 wt% of the total wt% of the glass composition.

[0140] The glass fibers may comprise substantially no ZnO i.e. the glass fibers may be substantially zinc-free fibers. The glass fibers may comprise no ZnO i.e. the glass fibers may be zinc-free fibers.

[0141] The glass fibers may comprise BaO in a range from about 0.1 to about 3 wt% of the total wt% of the glass composition. The glass fibers may comprise BaO in a range from about 0.5 to about 1 wt% of the total wt% of the glass composition, such as about 1 wt%. The glass fibers may comprise BaO in a range from about 1 to about 3 wt% of the total wt% of the glass composition, such as about 1.1 to about 3 wt%.

[0142] The glass fibers may comprise substantially no BaO i.e. the glass fibers may be substantially barium-free fibers. The group of glass fibers may comprise no BaO i.e. the glass fibers may be barium-free fibers.

[0143] The glass fibers may comprise I 2O in a range from about 0.1 to about 1 wt% of the total wt% of the glass composition. The glass fibers may comprise I 2O in a range from about 0.1 to about 0.4 wt% of the total wt% of the glass composition. The glass fibers may comprise I 2O in a range from about 0.5 to about 1 wt% of the total wt% of the glass composition.

[0144] The glass fibers may comprise substantially no Li2O i.e. the glass fibers may be substantially lithium-free fibers. The glass fibers may contain less than 0.2 wt% Li2O of the total wt% of the glass composition. The glass fibers may comprise no Li2O i.e. the glass fibers may be lithium-free fibers.

[0145] The glass fibers may comprise Na2O and K2O in a range from about 0.1 to about 5 wt% of the total wt% of the glass composition. The glass fibers may comprise Na2O and K2O in a range from about 0.1 to about 4 wt% of the total wt% of the glass composition, such as about 0.5 to about 4 wt% of the total wt% of the glass composition. The glass fibers may comprise a total of Na20 and K2O in a range from about 0.1 to about 2 wt% of the total wt% of the glass composition, such as about 0.1 to about 1 wt% of the total wt% of the glass composition. The glass fibers may comprise a total of Na2O and K2O in a range from about 0.1 to about 0.3 wt% of the total wt% of the glass composition. The glass fibers may comprise Na2O and K2O in about 0.1 to about 0.2 wt% of the total wt% of the glass composition. The glass fibers may comprise Na2O and K2O in about 0.9 wt% of the total wt% of the glass composition. The glass fibers may comprise Na2O and K2O in about 0.8 wt% of the total wt% of the glass composition. The glass fibers may comprise Na2O and K2O in about 1.2 wt% of the total wt% of the glass composition.

[0146] The glass fibers may comprise substantially no Na2O or K2O i.e. the glass fibers may be substantially sodium- and potassium-free fibers. The glass fibers may comprise no Na2O or K2O i.e. the glass fibers may be sodium- and potassium-free fibers.

[0147] The glass fibers may comprise TiCh in a range from about 0.1 to about 5 wt% of the total wt% of the glass composition. The glass fibers may comprise TiCh in a range from about 0.1 to about 4 wt% of the total wt% of the glass composition. The glass fibers may comprise TiCh in a range from about 0.1 to about 0.2 wt% of the total wt% of the glass composition, such as about 0.1 to about 1.5 wt%. The glass fibers may comprise TiCh in a range from about 0.2 to about 0.5 wt% of the total wt% of the glass composition. The glass fibers may comprise TiCh in about 0.5 wt% of the total wt% of the glass composition. The glass fibers may comprise TiC>2 in about 1.5 wt% of the total wt% of the glass composition. The glass fibers may comprise TiC>2 in about 2.5 wt% of the total wt% of the glass composition.

[0148] The glass fibers may comprise substantially no TiCh i.e. the glass fibers may be substantially titanium-free fibers. The glass fibers may comprise no TiCh i.e. the glass fibers may be titanium-free fibers.

[0149] The glass fibers may comprise ZrCh in a range from about 0.1 to about 1 wt% of the total wt% of the glass composition. The glass fibers may comprise ZrCh in a range from about 0.1 to about 0.4 wt% of the total wt% of the glass composition. The glass fibers may comprise ZrCh in a range from about 0.5 to about 1 wt% of the total wt% of the glass composition. The glass fibers may comprise substantially no ZrCh i.e. the glass fibers may be substantially zirconium-free fibers. The glass fibers may comprise no ZrCh i.e. the glass fibers may be zirconium-free fibers.

[0150] The glass fibers may comprise Fe20s in a range from about 0.1 to about 2 wt% of the total wt% of the glass composition. The glass fibers may comprise Fe20s in a range from about 0.1 to about 0.8 wt% of the total wt% of the glass composition. The glass fibers may comprise Fe20s in a range from about 0.2 to about 0.4 wt% of the total wt% of the glass composition. The glass fibers may comprise Fe20s in about 0.1 wt% of the total wt% of the glass composition. The glass fibers may comprise Fe20s in about 0.2 wt% of the total wt% of the glass composition.

[0151] The glass fibers may comprise substantially no Fe20s i.e. the glass fibers may be substantially iron-free fibers. The glass fibers may comprise no Fe20s i.e. the glass fibers may be iron-free fibers.

[0152] The glass fibers may comprise F2 in a range from about 0.1 to about 2 wt% of the total wt% of the glass composition. The glass fibers may comprise F2 in a range from about 0.1 to about 1 wt% of the total wt% of the glass composition. The glass fibers may comprise F2 in a range from about 0.2 to about 0.7 wt% of the total wt% of the glass composition. The glass fibers may comprise F2 in about 0.1 wt% of the total wt% of the glass composition.

[0153] The glass fibers may comprise substantially no F2 i.e. the glass fibers may be substantially fluoride-free fibers. The glass fibers may contain less than 0.2 wt% F2 of the total wt% of the glass composition. The glass fibers may comprise no F2 i.e. the glass fibers may be fluoride- free fibers. Without wishing to be bound by theory, fluoride-free or substantially fluoride-free fibers are more environmentally friendly than fluoride-containing fibers.

[0154] The glass fibers may comprise a composition comprising:

[0155] While various components in the glass may be expressed as a range, the total wt% of the composition adds up to 100 wt%. The glass fibers may comprise boron-containing E-glass, boron-free E-glass, ECR-glass, H glass, or a mixture thereof. The glass fibers may comprise boron-containing E-glass fibers. The glass fibers may comprise boron-free E-glass fibers. The glass fibers may comprise ECR- glass fibers. The glass fibers may comprise a mixture of boron-containing E-glass, and boron- free E-glass fibers. The glass fibers may comprise a mixture of boron-containing E-glass, and ECR-glass fibers. The glass fibers may comprise a mixture of boron-free E-glass fibers, and ECR-glass fibers. The glass fibers may comprise a mixture of boron-containing E-glass, boron- free E-glass fibers, and ECR-glass fibers. The glass fibers may comprise H glass.

[0156] The composition of boron-containing E-glass may comprise:

[0157] While various components in the E-glass may be expressed as a range, the total wt% of the composition adds up to 100 wt%. The composition of boron-free E-glass may comprise:

[0158] While various components in the E-glass may be expressed as a range, the total wt% of the composition adds up to 100 wt%. In this instance, the boron-free E-glass does not comprise F2.

[0159] Alternatively or in addition, the composition of boron-free E-glass may comprise:

[0160] While various components in the E-glass may be expressed as a range, the total wt% of the composition adds up to 100 wt%. In this instance, the boron-free E-glass comprises F2.

[0161] The composition of ECR-glass may comprise:

[0162] While various components in the ECR-glass may be expressed as a range, the total wt% of the composition adds up to 100 wt%. In this instance, the ECR-glass comprises no or substantially no B2O3 nor F2. Boron-free ECR-glass fibers are commercially available from Owens Corning as Advantex™ glass fibers.

[0163] H glass and the method by which it can be prepared is disclosed in US11214512, the content of which is incorporated herein by reference in its entirety. The composition of H glass may comprise:

[0164] SiO2 in an amount from 55.0 to 60.4% by weight;

[0165] AI2O3 in an amount from 19.0 to 25.0% by weight;

[0166] CaO in an amount from 7 to 12.0% by weight;

[0167] MgO in an amount from 8.0 to 15.0% by weight;

[0168] Na2O in an amount from 0 to 1.0% by weight; and

[0169] TiC>2 in an amount from 0.0 to 1.5% by weight, expressed as percentages by weight based on the weight of the entire composition, wherein the weight percent ratio of AhCE / MgO is less than 2.0, wherein the combined amounts of SiCE, AI2O3, MgO, and CaO is at least 98% by weight and less than 99.5% by weight, wherein the sum of the amounts of B2O3, Li2O, and fluorine is less than 0.2% by weight, and wherein said glass composition has a fiberizing temperature no greater than 2,500° F.

[0170] The composition of H glass may comprise 19.5 to 21% by weight AI2O3.

[0171] The combined amounts in H glass of MgO and CaO is greater than 20% by weight.

[0172] The combined amounts in H glass of MgO and CaO is less than 22% by weight.

[0173] The weight percent ratio in H glass of AhOs / MgO is no greater than 1.8.

[0174] The combined amounts in H glass of Fe2O3, TiO2, K2O, and Na2O is below 1.5% by weight. The composition of H glass is free or substantially free of B2O3.

[0175] The composition of H glass is free of Li2O.

[0176] The weight of the glass fibers in the precursor mat may be in the range of about 30 to about 170 gsm (grams per square meter). The weight of the glass fibers in the precursor mat may be in the range of about 40 to about 150 gsm. The weight of the glass fibers in the precursor mat may be > about 40 gsm. The weight of the glass fibers in the precursor mat may be > about 45 gsm. The weight of the glass fibers in the precursor mat may be > about 50 gsm. The weight of the glass fibers in the precursor mat may be > about 55 gsm. The weight of the glass fibers in the precursor mat may be > about 60 gsm.

[0177] The weight of the glass fibers in the precursor mat may be < about 170 gsm. The weight of the glass fibers in the precursor mat may be < about 165 gsm. The weight of the glass fibers in the precursor mat may be < about 160 gsm. The weight of the glass fibers in the precursor mat may be < about 155 gsm. The weight of the glass fibers in the precursor mat may be < about 150 gsm. The weight of the glass fibers in the precursor mat may be < about 140 gsm. The weight of the glass fibers in the precursor mat may be < about 135 gsm. The weight of the glass fibers in the precursor mat may be < about 130 gsm.

[0178] The weight of the glass fibers in the precursor mat may be in the range of about 60 to about 130 gsm.

[0179] The weight of the glass fibers in the precursor mat may be about 65 gsm.

[0180] The first binder and coating composition are applied in two separate stages during the manufacture of the coated non-woven fibrous mat. The first binder, or combination thereof, is applied first in the formation of the precursor mat, and the coating composition (comprising the aqueous composition defined herein) is applied secondly in the formation of the final coated non-woven fibrous mat.

[0181] The first binder is selected from one or more (e.g. 1, 2, 3, 4, 5, or more) urea formaldehyde resins, such as modified urea formaldehyde resins. Alternatively, the first binder may be selected from a formaldehyde-free (or no-added formaldehyde (“NAF”)) binder. Binders which are free of added formaldehyde are environmentally friendly i.e. “green”.

[0182] The first binder may be selected from one or more (e.g. 1, 2, 3, 4, 5, or more) polycarboxylic acid binders, polyvinyl alcohol binders, or combination thereof.

[0183] The first binder may be a water-soluble or water-dispersible binder. The binder may be a water- soluble binder. The binder may be a water-dispersible binder. The binder composition may comprise one or more of any water-based emulsion or solution.

[0184] The polycarboxylic acid binder may be a homopolymer or copolymer prepared from one or more (e.g. 1, 2, 3, 4, 5 or more) unsaturated carboxylic acid compounds including but not necessarily limited to, acrylic acid, methacrylic acid, crotonic acid, isocrotonic acid, maleic acid, cinnamic acid, 2-methylmaleic acid, itaconic acid, 2-methylitaeonic acid, a,P- methyleneglutaric acid, and the like. Methods for polymerising these acids are known to the skilled person. In this instance, the polycarboxylic acid binder is a homopolymer or copolymer comprising at least one or more (e.g. 1, 2, 3, 4, or 5) repeat units, and the or each repeat unit comprises a -COOH group.

[0185] Alternatively, the polycarboxylic acid binder may be prepared from unsaturated anhydrides including, but not necessarily limited to, maleic anhydride, methacrylic anhydride, and the like, as well as mixtures thereof. Methods for polymerising these anhydrides are known to the skilled person. In this instance, the polycarboxylic acid binder is a homopolymer or copolymer comprising at least one or more (e.g. 1, 2, 3, 4, or 5) repeat units, and the or each repeat unit comprises a -CO-O-CO- group.

[0186] The polycarboxylic acid binder may further comprise a homopolymer or copolymer prepared from one or more (e.g. 1, 2, 3, 4, 5 or more) unsaturated carboxylic acid ester compounds including, but not necessarily limited to, methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, methyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, glycidyl methacrylate, vinyl acetate, and the like. Methods for preparing these polymers are known to the skilled person. In this instance, the polycarboxylic acid binder is a homopolymer or copolymer comprising at least one or more (e.g. 1, 2, 3, 4, or 5) repeat units, and the or each repeat unit comprises a -COOR group, and R is selected from the group consisting of methyl, ethyl, butyl (n-, i-, or t-), and 2,3-epoxypropyl as appropriate.

[0187] When the polycarboxylic acid binder comprises a mixture of a polymer (e.g. a homo- or copolymer) of an unsaturated carboxylic acid (e.g. polyacrylic acid binder) and a polymer (e.g. a homo- or co-polymer) of an unsaturated carboxylic acid ester (e.g. polymethyl methacrylate), the wt% ratio of the polymer of the unsaturated carboxylic acid to the polymer of the unsaturated carboxylic acid ester may be in the range of about 1 : about 0.01 wt% to about 1 : about 1 wt% of the total solids in the binder composition. The wt% ratio of the polymer of the unsaturated carboxylic acid to the polymer of the unsaturated carboxylic acid ester may be in the range of about 1 : about 0.1 wt% to about 1 : about 0.8 wt% of the total solids in the binder composition. The wt% ratio of the polymer of the unsaturated carboxylic acid to the polymer of the unsaturated carboxylic acid ester may be in the range of about 1 : about 0.2 wt% to about 1 : about 0.5 wt% of the total solids in the binder composition. The wt% ratio of the polymer of the unsaturated carboxylic acid (e.g. polyacrylic acid binder) to the polymer of the unsaturated carboxylic acid ester (e.g. polymethyl methacrylate) may be about 1 : about 0.4 wt% of the total solids in the binder composition.

[0188] The polycarboxylic acid binder may be a homopolymer or copolymer of polyacrylic acid. The polycarboxylic acid binder is a homopolymer of polyacrylic acid i.e. the polymer is synthesised from acrylic acid. The weight average molecular weight (Mw) of the polycarboxylic acid binder, such as polyacrylic acid binder or polymethyl methacrylate binder, may be less than 10000 g / mole, such as less than 5000 g / mole, and for example about 3000 g / mole or less, e.g. about 2000 g / mole.

[0189] The polycarboxylic acid binder may comprise polymethyl methacrylate.

[0190] The polycarboxylic acid binder may comprise polyacrylic acid and polymethyl methacrylate.

[0191] The pH of the first binder may be low, for example, about 3 or less, such as about 2.5 or less, e.g. about 2 or less. The pH of the binder can be adjusted by adding a suitable acid, such as sulfuric acid. The low pH of the binder can provide processing advantages. An example of the processing advantages include a reduction in cure temperature or time. The pH of the first binder may be about pH 2 to about pH 3. The first binder, or combination thereof, may additionally contain a polyol containing at least two hydroxyl groups. Any suitable polyol may be used provided the polyol is sufficiently nonvolatile such that it will substantially remain available for reaction with the polyacid in the composition during heating and curing operations. The polyol may be a compound with a molecular weight less than about 1000 and bearing at least two hydroxyl groups such as ethylene glycol, glycerol, pentaerythritol, trimethylol propane, sorbitol, sucrose, glucose, resorcinol, catechol, pyrogallol, gly collated ureas, 1,4-cyclohexane diol, diethanolamine, or triethanolamine.

[0192] The polyol may be glycerol.

[0193] When the polycarboxylic acid binder comprises a mixture of a polymer (e.g. a homo- or copolymer) of an unsaturated carboxylic acid and a polyol, the wt% ratio of the unsaturated carboxylic acid polymer to polyol may be in the range of about 1 : about 0.01 wt% to about 1 : about 1 wt% of the total solids in the binder composition. The wt% ratio of the unsaturated carboxylic acid polymer to polyol may be in the range of about 1 : about 0.1 wt% to about 1 : about 0.8 wt% of the total solids in the binder composition. The wt% ratio of the unsaturated carboxylic acid polymer to polyol may be in the range of about 1 : about 0.2 wt% to about 1 : about 0.5 wt% of the total solids in the binder composition. The wt% ratio of the unsaturated carboxylic acid polymer (e.g. polyacrylic acid binder) to polyol (e.g. glycerol) may be about 1 : about 0.3 wt% of the total solids in the binder composition, such as about 1 : about 0.25 wt% of the total solids in the binder composition.

[0194] The first binder may be a combination of polyacrylic acid, polymethyl methacylate, and glycerol. The first binder may be a combination of (a) polyacrylic acid and glycerol, and (b) polymethyl methacrylate latex. The wt% ratio of polyacrylic acid : glycerol may be about 75% to about 25% of the total solids in the binder composition. The ratio of (a) : (b) may be about 75% to about 25% of the total solids in the binder composition. The final wt% ratio of polyacrylic acid : glycerol : polymethyl methacrylate overall may be about 56% : about 19% : about 25% of the total solids in the binder composition.

[0195] In certain embodiments, the polyol does not comprise a -hydroxyalkylamide group. Examples of such polyols, include but are not limited to, bis[N,N-di(hydroxyethyl)]adipamide. The first binder may be a polyvinyl alcohol binder. Polyvinyl alcohols are water-soluble polymers which may be manufactured by the hydrolysis (saponification) of polyvinyl acetate. Polyvinyl alcohols are typically described in terms of their degree of hydrolysis (% hydrolysis) and / or their weight average molecular weight (Mw).

[0196] The weight average molecular weight (Mw) of the polyvinyl alcohol binder, may be less than 10000 g / mole, such as less than 5000 g / mole, and for example about 3000 g / mole or less, e.g. about 2000 g / mole.

[0197] The polyvinyl alcohol binder may have a % hydrolysis which is about > 80%. The % hydrolysis may be > about 85%. The % hydrolysis may be > about 90%. The % hydrolysis may be > about 91%. The % hydrolysis may be > about 92%. The % hydrolysis may be > about 93%. The % hydrolysis may be > about 94%. The % hydrolysis may be > about 95%. The % hydrolysis may be > about 96%. The % hydrolysis may be > about 97%. The % hydrolysis may be > about 98%. The % hydrolysis may be > about 99%.

[0198] The % hydrolysis may be > about 98-99%. In this instance, the polyvinyl alcohol binder has a high purity, and is particularly suitable for use in coated non-woven fibrous mats in gypsum boards.

[0199] The polyvinyl alcohol binder may be liquid or a solid. When the polyvinyl alcohol binder is a powder, it may be co-cast with the blend of glass fibers in the aqueous solution.

[0200] The poly carboxylic acid binder may be a copolymer prepared from one or more (e.g. 1, 2, 3, 4, 5 or more) unsaturated carboxylic acid compounds and one or more (e.g. 1, 2, 3, 4, 5 or more) aryl vinyl compounds. The unsaturated carboxylic acid include but not necessarily limited to, acrylic acid, methacrylic acid, crotonic acid, isocrotonic acid, maleic acid, cinnamic acid, 2-methylmaleic acid, itaconic acid, 2-methylitaeonic acid, a,P-methyleneglutaric acid, and the like. The aryl vinyl compounds include but are not limited to, styrene, methylstyrene (2-, 3-, or 4-), ethylstyrene (2-, 3-, or 4-), n-butyl styrene (2-, 3-, or 4-), iso-butyl styrene (2-, 3- , or 4-), tert-butyl styrene (2-, 3-, or 4-), a-m ethyl styrene (also known as isopropenylbenzene), P-methylstyrene (also known as propenylbenzene). Methods for preparing these copolymers are known to the skilled person. In this instance, the polycarboxylic acid binder is a copolymer comprising (a) a repeat unit comprising a -COOH group, and (b) a repeat unit comprising a substituted or unsubstituted styrenyl group.

[0201] The first binder is styrene acrylic latex. In this instance, the copolymer is prepared from an unsaturated carboxylic acid which is acrylic acid, and an aryl vinyl compound which is styrene.

[0202] The wt% of the first binder, or combination thereof, may be in the range of about 5 wt% to about 50 wt% of the total solids in the precursor mat. The wt% of the first binder, or combination thereof, may be in the range of about 10 wt% to about 40 wt% of the total solids in the precursor mat. The wt% of the first binder, or combination thereof, may be > about 10 wt% of the total solids in the precursor mat. The wt% of the first binder, or combination thereof, may be > about 11 wt% of the total solids in the precursor mat. The wt% of the first binder, or combination thereof, may be > about 12 wt% of the total solids in the precursor mat. The wt% of the first binder, or combination thereof, may be > about 13 wt% of the total solids in the precursor mat. The wt% of the first binder, or combination thereof, may be > about 14 wt% of the total solids in the precursor mat.

[0203] The wt% of the first binder, or combination thereof, may be < about 35 wt% of the total solids in the precursor mat. The wt% of the first binder, or combination thereof, mat may be < about 30 wt% of the total solids in the precursor mat. The wt% of the first binder, or combination thereof, may be < about 25 wt% of the total solids in the precursor mat.

[0204] The wt% of the first binder, or combination thereof, may be in the range of about 15 wt% to about 25 wt% of the total solids in the precursor mat.

[0205] The wt% of the first binder, or combination thereof, may be about 23 wt% of the total solids in the precursor mat.

[0206] The amounts of binder, hydrophobically modified cellulose, inorganic filler, dispersant, and optional additives (if any) may each be described as a percent weight based on the total solids in the dried coating composition. The percent weight of each component of the dried composition will total 100 wt% total solids in the dried coating composition. The dried composition may comprise the hydrophobic binder in a range of about 1 wt% to about 15 wt% of the total solids in the dried composition. The dried composition may comprise the hydrophobic binder in a range of about 3 wt% to about 10 wt% of the total solids in the dried composition. The dried composition may comprise the hydrophobic binder in an amount > 3 wt% of the total solids in the dried composition. The dried composition may comprise the hydrophobic binder in an amount > 3.5 wt% of the total solids in the dried composition. The dried composition may comprise the hydrophobic binder in an amount > 4 wt% of the total solids in the dried composition. The dried composition may comprise the hydrophobic binder in an amount > 4.5 wt% of the total solids in the dried composition. The dried composition may comprise the hydrophobic binder in an amount > 5 wt% of the total solids in the dried composition.

[0207] The dried composition may comprise the hydrophobic binder in an amount < 10 wt% of the total solids in the dried composition. The dried composition may comprise the hydrophobic binder in an amount < 9.5 wt% of the total solids in the dried composition. The dried composition may comprise the hydrophobic binder in an amount < 9 wt% of the total solids in the dried composition. The dried composition may comprise the hydrophobic binder in an amount < 8.5 wt% of the total solids in the dried composition. The dried composition may comprise the hydrophobic binder in an amount < 8 wt% of the total solids in the dried composition. The dried composition may comprise the hydrophobic binder in an amount < 7.5 wt% of the total solids in the dried composition.

[0208] The dried composition may comprise the hydrophobic binder in a range of about 5 wt% to about 8 wt%, such as about 5 wt% to about 7 wt% of the total solids in the dried composition.

[0209] The dried composition may comprise the hydrophobically modified cellulose in a range of about 0.05 wt% to about 1 wt% total solids in the dried composition. The dried composition may comprise the hydrophobically modified cellulose in an amount of > about 0.1 wt% total solids in the dried composition. The dried composition may comprise the hydrophobically modified cellulose in an amount of > about 0.12 wt% total solids in the dried composition. The dried composition may comprise the hydrophobically modified cellulose in an amount of > about 0.14 wt% total solids in the dried composition. The dried composition may comprise the hydrophobically modified cellulose in an amount of > about 0.16 wt% total solids in the dried composition. The dried composition may comprise the hydrophobically modified cellulose in an amount of > about 0.18 wt% total solids in the dried composition. The dried composition may comprise the hydrophobically modified cellulose in an amount of > about 0.2 wt% total solids in the dried composition.

[0210] The dried composition may comprise the hydrophobically modified cellulose in an amount of < about 0.5 wt% total solids in the dried composition. The dried composition may comprise the hydrophobically modified cellulose in an amount of < about 0.48 wt% total solids in the dried composition. The dried composition may comprise the hydrophobically modified cellulose in an amount of < about 0.46 wt% total solids in the dried composition. The dried composition may comprise the hydrophobically modified cellulose in an amount of < about 0.44 wt% total solids in the dried composition. The dried composition may comprise the hydrophobically modified cellulose in an amount of < about 0.42 wt% total solids in the dried composition. The dried composition may comprise the hydrophobically modified cellulose in an amount of < about 0.4 wt% total solids in the dried composition.

[0211] The dried composition may comprise the hydrophobically modified cellulose in a range of about 0.2 wt% to about 0.4 wt%, such as about 0.3 wt%, of the total solids in the dried composition.

[0212] The dried composition may comprise the inorganic filler in a range of about 50 wt% to about 98 wt% total solids in the dried composition. The dried composition may comprise the filler in an amount of > about 50 wt% total solids in the dried composition. The dried composition may comprise the filler in an amount of > about 55 wt% total solids in the dried composition. The dried composition may comprise the filler in an amount of > about 60 wt% total solids in the dried composition. The dried composition may comprise the filler in an amount of > about 65 wt% total solids in the dried composition. The dried composition may comprise the filler in an amount of > about 70 wt% total solids in the dried composition. The dried composition may comprise the filler in an amount of > about 75 wt% total solids in the dried composition. The dried composition may comprise the filler in an amount of > about 80 wt% total solids in the dried composition. The dried composition may comprise the filler in an amount of > about 85 wt% total solids in the dried composition. The dried composition may comprise the filler in an amount of > about 90 wt% total solids in the dried composition. The dried composition may comprise the inorganic filler in an amount of < about 98 wt% total solids in the dried composition. The dried composition may comprise the filler in an amount of < about 97.5 wt% total solids in the dried composition. The dried composition may comprise the filler in an amount of < about 97 wt% total solids in the dried composition. The dried composition may comprise the filler in an amount of < about 96.5 wt% total solids in the dried composition. The dried composition may comprise the filler in an amount of < about 96 wt% total solids in the dried composition. The dried composition may comprise the filler in an amount of < about 95.5 wt% total solids in the dried composition. The dried composition may comprise the filler in an amount of < about 95 wt% total solids in the dried composition.

[0213] The dried composition may comprise the inorganic filler in a range of about 91 wt% to about 95 wt%, such as about 92 wt% to about 94 wt%, of the total solids in the dried composition.

[0214] The dried composition may comprise the dispersant in a range of about 0.001 wt% to about 0.15 wt% total solids in the dried composition, such as about 0.001 wt% to about 0.08 wt% total solids in the dried composition. The dried composition may comprise the dispersant in an amount of > about 0.001 wt% total solids in the dried composition. The dried composition may comprise the dispersant in an amount of > about 0.01 wt% total solids in the dried composition. The dried composition may comprise the dispersant in an amount of > about 0.02 wt% total solids in the dried composition. The dried composition may comprise the dispersant in an amount of > about 0.03 wt% total solids in the dried composition. The dried composition may comprise the dispersant in an amount of > about 0.04 wt% total solids in the dried composition. The dried composition may comprise the dispersant in an amount of > about 0.05 wt% total solids in the dried composition. The dried composition may comprise the dispersant in an amount of > about 0.06 wt% total solids in the dried composition.

[0215] The dried composition may comprise the dispersant in an amount of < about 0.13 wt% total solids in the dried composition. The dried composition may comprise the dispersant in an amount of < about 0.12 wt% total solids in the dried composition. The dried composition may comprise the dispersant in an amount of < about 0.11 wt% total solids in the dried composition. The dried composition may comprise the dispersant in an amount of < about 0.1 wt% total solids in the dried composition. The dried composition may comprise the dispersant in an amount of < about 0.09 wt% total solids in the dried composition. The dried composition may comprise the dispersant in an amount of < about 0.08 wt% total solids in the dried composition. The dried composition may comprise the dispersant in an amount of < about 0.07 wt% total solids in the dried composition.

[0216] The dried composition may comprise the dispersant in a range of about 0.06 wt% to about 0.07 wt%, such as about 0.065 wt% or 0.07 wt%, of the total solids in the dried composition.

[0217] If the coating comprises a biocide, the dried composition may comprise the biocide in a range of about 0.001 wt% to about 0.08 wt% total solids in the dried composition. The dried composition may comprise the biocide in an amount of > about 0.001 wt% total solids in the dried composition. The dried composition may comprise the biocide in an amount of > about 0.01 wt% total solids in the dried composition. The dried composition may comprise the biocide in an amount of > about 0.02 wt% total solids in the dried composition. The dried composition may comprise the biocide in an amount of > about 0.03 wt% total solids in the dried composition.

[0218] The dried composition may comprise the biocide in an amount of < about 0.13 wt% total solids in the dried composition. The dried composition may comprise the biocide in an amount of < about 0.12 wt% total solids in the dried composition. The dried composition may comprise the biocide in an amount of < about 0.11 wt% total solids in the dried composition. The dried composition may comprise the biocide in an amount of < about 0.1 wt% total solids in the dried composition. The dried composition may comprise the biocide in an amount of < about 0.09 wt% total solids in the dried composition. The dried composition may comprise the biocide in an amount of < about 0.08 wt% total solids in the dried composition. The dried composition may comprise the biocide in an amount of < about 0.07 wt% total solids in the dried composition.

[0219] The dried composition may comprise the biocide in a range of about 0.03 wt% to about 0.07 wt%, such as about 0.05 wt%, of the total solids in the dried composition.

[0220] The dried composition may contain other optional additives such as those described herein in an amount from about 0.01 wt % to about 0.08 wt%, such as about 0.01 to about 0.06 wt% total solids in the dried composition.

[0221] Alternatively, the dried composition may contain no other optional additives. The weight of the dried coating composition may be in the range of about 130 to about 350 gsm (grams per square meter). The weight of the dried coating composition may be in the range of about 180 to about 340 gsm.

[0222] The weight of the dried coating composition may be > about 170 gsm. The weight of the dried coating composition may be > about 180 gsm. The weight of the dried coating composition may be > about 190 gsm. The weight of the dried coating composition may be > about 200 gsm. The weight of the dried coating composition may be > about 210 gsm.

[0223] The weight of the dried coating composition may be < about 340 gsm. The weight of the dried coating composition may be < about 320 gsm. The weight of the dried coating composition may be < about 300 gsm. The weight of the dried coating composition may be < about 290 gsm. The weight of the dried coating composition may be < about 280 gsm. The weight of the dried coating composition may be < about 270 gsm. The weight of the dried coating composition may be < about 260 gsm. The weight of the dried coating composition may be < about 250 gsm.

[0224] The weight of the dried coating composition may be in the range of about 200 to about 270 gsm, such as about 210 to about 250 gsm.

[0225] The total weight of the (dried) coated non-woven fibrous mat may be in the range of about 200 to about 430 gsm (grams per square meter). The total weight of the coated non-woven fibrous mat may be in the range of about 250 to about 380 gsm. The total weight of the coated nonwoven fibrous mat may be > about 260 gsm. The total weight of the coated non-woven fibrous mat may be > about 270 gsm. The total weight of the coated non-woven fibrous mat may be > about 280 gsm. The total weight of the coated non-woven fibrous mat may be > about 285 gsm. The total weight of the coated non-woven fibrous mat may be > about 290 gsm. The total weight of the coated non-woven fibrous mat may be > about 295 gsm. The total weight of the coated non-woven fibrous mat may be > about 300 gsm.

[0226] The total weight of the coated non-woven fibrous mat may be < about 380 gsm. The total weight of the coated non-woven fibrous mat may be < about 370 gsm. The total weight of the coated non-woven fibrous mat may be < about 360 gsm. The total weight of the coated non- woven fibrous mat may be < about 350 gsm. The total weight of the coated non-woven fibrous mat may be < about 355 gsm. The total weight of the coated non-woven fibrous mat may be < about 340 gsm.

[0227] The total weight of the coated non-woven fibrous mat may be in the range of about 285 to about 355 gsm, such as about 300 to 330 gsm.

[0228] The thickness (or caliper) of the coated non-woven fibrous mat may be measured in accordance with ASTM DI 777. The thickness of the coated non-woven fibrous mat may be in the range of about 0.3 mm to about 2 mm, as measured in accordance with ASTM D1777. The thickness of the coated non-woven fibrous mat may be > 0.3 mm. The thickness of the coated non-woven fibrous mat may be > 0.35 mm. The thickness of the bonded non-woven fibrous mat may be > 0.4 mm. The thickness of the coated non-woven fibrous mat may be > 0.45 mm. The thickness of the coated non-woven fibrous mat may be > 0.5 mm. The thickness of the coated non-woven fibrous mat may be > 0.55 mm. The thickness of the coated non-woven fibrous mat may be > 0.6 mm.

[0229] The thickness of the coated non-woven fibrous mat may be < 2 mm, measured in accordance with ASTM D1777. The thickness of the coated non-woven fibrous mat may be < 1.7 mm. The thickness of the coated non-woven fibrous mat may be < 1.6 mm. The thickness of the coated non-woven fibrous mat may be < 1.5 mm. The thickness of the coated non-woven fibrous mat may be < 1.4 mm. The thickness of the coated non-woven fibrous mat may be < 1.3 mm. The thickness of the coated non-woven fibrous mat may be < 1.2 mm. The thickness of the coated non-woven fibrous mat may be < 1.1 mm. The thickness of the coated non-woven fibrous mat may be < 1 mm. The thickness of the coated non-woven fibrous mat may be < 0.9 mm. The thickness of the coated non-woven fibrous mat may be < 0.8 mm.

[0230] The thickness of the coated non-woven fibrous mat may be in the range of about 0.65 mm to about 0.75 mm, measured in accordance with ASTM D1777.

[0231] A Cobb test determines the ability of the coated non-woven fibrous mat to resist the penetration of water. In this respect, the lower the Cobb value the better as this demonstrates that the coated non-woven fibrous mat has a greater hydrophobicity to water. The coated non-woven fibrous mat may have an average Cobb value of < about 25 g / m2when measured in accordance with European Standard EN20535 (as adapted to non-woven fibrous mats). The coated non-woven fibrous mat may have an average Cobb value of between about 10 and about 25 g / m2when measured in accordance with European Standard EN20535 (as adapted to non-woven fibrous mats). The coated non-woven fibrous mat may have an average Cobb value of > about 10 g / m2. The coated non-woven fibrous mat may have an average Cobb value of > about 11 g / m2. The coated non-woven fibrous mat may have an average Cobb value of > about 12 g / m2. The coated non-woven fibrous mat may have an average Cobb value of > about 14 g / m2. The coated non-woven fibrous mat may have an average Cobb value of > about 16 g / m2. The coated non-woven fibrous mat may have an average Cobb value of > about 17 g / m2. The coated non-woven fibrous mat may have an average Cobb value of > about 18 g / m2.

[0232] The coated non-woven fibrous mat may have an average Cobb value of < about 25 g / m2when measured in accordance with European Standard EN20535 (as adapted to non-woven fibrous mats). The coated non-woven fibrous mat may have an average Cobb value of < about 24 g / m2. The coated non-woven fibrous mat may have an average Cobb value of < about 23 g / m2. The coated non-woven fibrous mat may have an average Cobb value of < about 22 g / m2. The coated non-woven fibrous mat may have an average Cobb value of < about 21 g / m2.

[0233] The coated non-woven fibrous mat may have an average Cobb value of between about 19 and about 20 g / m2when measured in accordance with European Standard EN20535 (as adapted to non-woven fibrous mats).

[0234] An air permeability test measures airflow through an area of substrate, such as the coated nonwoven mat of the present invention. The coated non-woven fibrous mat may have an air permeability as measured at 1220 Pa in accordance with ASTM D737. The coated non-woven fibrous mat may have an average air permeability in the range of about 45 L.m'fs'1to about 53 L.m'2.s_|(L.m'2.s_|= L / m2 / second), measured in accordance with ASTM D737. The coated non-woven fibrous mat may have an average air permeability > about 45 L.m^.s'1. The coated non-woven fibrous mat may have an average air permeability > about 46 L.m^.s'1. The coated non-woven fibrous mat may have an average air permeability > about 47 L.m^.s'1. The coated non-woven fibrous mat may have an average air permeability > about 48 L.m^.s'1. The coated non-woven fibrous mat may have an average air permeability > about 49 L.m^.s'1. The coated non-woven fibrous mat may have an average air permeability < about 53 L.m^.s'1, measured in accordance with ASTM D737. The coated non-woven fibrous mat may have an average air permeability < about 52.5 L.m^.s'1. The coated non-woven fibrous mat may have an average air permeability < about 52 L.m^.s'1. The coated non-woven fibrous mat may have an average air permeability < about 51.5 L.m^.s'1. The coated non-woven fibrous mat may have an average air permeability < about 51 L.m^.s'1.

[0235] The coated non-woven fibrous mat may have an average air permeability in the range of about 49 L.m^.s'1to about 50 L.m^.s'1, measured in accordance with ASTM D737.

[0236] Methods for Manufacturing the Coated Non-Woven Fibrous Mat

[0237] Preparing the Precursor Mat by Co-Casting the Fibers and First Binder Before Impregnating the Precursor Mat

[0238] In another aspect, the present invention provides a method for manufacturing a coated nonwoven fibrous mat comprising the steps of

[0239] (v) providing a precursor mat comprising glass fibers and a first binder;

[0240] (vi) depositing the aqueous composition as described herein on the precursor mat;

[0241] (vii) coating the precursor mat with the aqueous composition with a knife-over-roll technique, wherein as the precursor mat and aqueous composition pass through a predetermined gap between the knife and the roll, the knife contacts the aqueous composition, the aqueous composition exhibits shear thinning on contact with the knife, and the precursor mat is coated with the aqueous composition; and

[0242] (viii) drying the coated precursor mat to form the coated non-woven fibrous mat.

[0243] The precursor mat may be prepared in a method comprising the steps of

[0244] (i) providing an aqueous mixture comprising glass fibers, and a first binder;

[0245] (ii) forming a dispersion of the aqueous mixture;

[0246] (iii) depositing the aqueous dispersion to form a wetlaid web of glass fibers, and first binder;

[0247] (iv) drying the wetlaid web of glass fibers, and first binder to form the precursor mat.

[0248] The steps for forming the precursor mat may also be referred to as a “co-casting” method. This is because an aqueous mixture of glass fibers is formed together with the first binder. The glass fibers, the first binder (or combination thereof), the precursor mat, and the aqueous composition, are as described above.

[0249] Alternatively, the precursor mat may be prepared in a method comprising the steps of

[0250] (i) providing an aqueous mixture comprising glass fibers;

[0251] (ii) depositing the aqueous mixture to form a wetlaid web of glass fibers;

[0252] (iii) applying an aqueous solution or dispersion of a first binder to the wetlaid web of glass fibers, to form a wetlaid web of glass fibers, and first binder;

[0253] (iv) drying the wetlaid web of glass fibers, and first binder to form the precursor mat.

[0254] The first binder may be applied to the web of glass fibers by a suitable binder applicator, such as a spray applicator or a curtain coater.

[0255] The flexible 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 first binder (or combination thereof) and water, and optionally other components such as surfactants, viscosity modifiers, defoaming agents, lubricants, biocides, and / or other chemical agents.

[0256] 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.

[0257] The first binder (or combination thereof) may optionally contain conventional additives as described above 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. The first binder (or combination thereof) may be added at any suitable point in the preparation of the aqueous mixture. For example, the binder (or combination thereof) may be added before, after, or at the same time as the glass fibers.

[0258] The first 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.

[0259] 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.

[0260] Once the binder has been applied to the wetlaid web of glass fibers, the wetlaid web is passed through at least one drying oven to remove remaining water and cure the binder composition. The fiber web may be further dried by a vacuum slot or other drying means to provide a fiber web.

[0261] 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.

[0262] The precursor mat is substantially or completely coated with the aqueous composition as defined above.

[0263] The aqueous composition of the present invention is prepared by any suitable method, such as mixing each component with water and the aqueous hydrophobic binder.

[0264] The coated non-woven fibrous mat is asymmetric. By “asymmetric”, we mean that the aqueous composition of the present invention does not completely impregnate the precursor mat. Instead, the aqueous composition coats or sits solely on one side of the precursor mat. In this respect, the aqueous composition will be detectable on coated side of the precursor mat but will not be detectable on the other (uncoated) side of the mat. The coated precursor mat is then dried to form the coated non-woven fibrous mat. Typically the coated precursor mat may be passed through at least one drying oven to remove any remaining water and to cure the binder. The mat may be further dried by a vacuum slot or other drying means to provide the coated non-woven fibrous mat as described above.

[0265] Printing the Coated Non-Woven Fibrous Mat

[0266] The coated non-woven mat of the present invention is opaque and colour stable. As such, it does not need to be printed with e.g. ink, or other indelible fluid suitable for printing. If desired, however, the method for manufacturing the coated non-woven fibrous mat may further comprise applying a liquid ink formulation to a first surface, a second surface, or both the first and second surfaces of the coated non-woven fibrous mat to coat or impregnate the first surface, the second surface, or both the first and second surfaces of the coated non-woven fibrous mat; and drying the liquid ink formulation to form a coated non-woven fibrous mat comprising a dried layer of ink.

[0267] A liquid paint formulation may be applied to the first surface of the coated non-woven fibrous mat to coat or impregnate the first surface of the coated non-woven fibrous mat. A liquid paint formulation may be applied to the second surface of the coated non-woven fibrous mat to coat or impregnate the second surface of the coated non-woven fibrous mat. A liquid paint formulation may be applied to both the first and second surfaces of the coated non-woven fibrous mat to coat or impregnate both the first and second surfaces of the coated non-woven fibrous mat.

[0268] Methods for drying the wet coated or impregnated non-woven fibrous mat to form a coated non-woven fibrous mat comprising a dried layer of paint are known to the skilled person. Methods include but are not limited to drying under ambient temperature and pressure, drying under hot air, and drying using infra-red technology.

[0269] In another aspect, the present invention provides coated non-woven fibrous mat comprising: a coated non-woven fibrous mat as described above, and the first surface, the second surface, or both the first and second surfaces comprise a a layer of ink. The coated non-woven fibrous mat is as described herein.

[0270] The first surface may comprise a layer of ink. The second surface may comprise a layer of ink. Both the first and second surfaces may comprise a layer of ink.

[0271] Uses for the Coated Non-Woven Fibrous Mat

[0272] When coated non-woven fibrous mats are produced using wet-laid procedures and the aqueous fiber dispersion or slurry is deposited onto a moving screen or conveyor, the resulting coated non-woven fibrous mats typically have a smooth surface (the surface in contact with the moving screen or conveyor) and a non-smooth surface (the surface not in contact with the moving screen or conveyor). The smooth surface is typically the presentation surface. For example, when the coated non-woven fibrous mat is attached to a construction board, the smooth surface is faces into the room and the non-smooth surface attaches to the board. As alternative use, the coated non-woven fibrous mat can be used for wall covering applications.

[0273] In another aspect, the present invention provides a construction board comprising: a first surface and a second surface opposite the first surface, a coated non-woven fibrous mat adhered to the first surface, the second surface or both the first and second surfaces, and wherein the coated non-woven fibrous mat is as described above.

[0274] The coated non-woven fibrous mat is as described herein.

[0275] The coated non-woven fibrous mat may be a facer in the construction board i.e. the facer is adhered to a first surface, a second surface or both first and second surfaces to form a construction board.

[0276] The construction board may be selected from the group consisting of a ceiling tile, gypsum board, building panel, isolation panel, and floorboard. The construction board may be a gypsum board.

[0277] The adhesion of the coated non-woven fibrous mat of the invention to a gypsum core may be determined in accordance with ASTM D4541. In this respect, the higher the adhesion value the better as this demonstrates that the coated non-woven fibrous mat is strongly adhered to the gypsum core.

[0278] The coated non-woven fibrous mat may have an average adhesion value of > about 420 Newtons when measured in accordance with ASTM D4541. The coated non-woven fibrous mat may have an average adhesion value of > about 420 to < about 450 N when measured in accordance with ASTM D4541. The coated non-woven fibrous mat may have an average adhesion value of > about 421 N. The coated non-woven fibrous mat may have an average adhesion value of > about 422 N. The coated non-woven fibrous mat may have an adhesion of > about 423 N. The coated non-woven fibrous mat may have an average adhesion value of > about 424 N. The coated non-woven fibrous mat may have an average adhesion value of > about 425 N.

[0279] The coated non-woven fibrous mat may have an average adhesion value of < about 450

[0280] Newtons when measured in accordance with ASTM D4541. The coated non-woven fibrous mat may have an average adhesion value of < about 445 N. The coated non-woven fibrous mat may have an average adhesion value of < about 440 N. The coated non-woven fibrous mat may have an average adhesion value of < about 435 N. The coated non-woven fibrous mat may have an average adhesion value of < about 430 N. The coated non-woven fibrous mat may have an average adhesion value of < about 429 N. The coated non-woven fibrous mat may have an average adhesion value of < about 428 N.

[0281] The coated non-woven fibrous mat may have an adhesion of > about 425 to < about 428 N when measured in accordance with ASTM D4541.

[0282] Embodiments and / or optional features of the invention have been described above. Any aspect of the invention may be combined with any other aspect of the invention, unless the context demands otherwise. Any of the embodiments or optional features of any aspect may be combined, singly or in combination, with any aspect of the invention, unless the context demands otherwise.

[0283] The invention will now be described further by reference to the following examples, which are intended to illustrate but not limit, the scope of the invention. Examples

[0284] Raw Materials Used

[0285] The following commercially available materials are used in the Examples:

[0286] Test Methods Determining the Weight Average Molecular Weight (Mw) of the Hydrophobicallv Modified Cellulose

[0287] GPC Method in Dimethylacetamide (DMAc)

[0288] The cellulose sample may be analyzed using an Agilent 1260 Infinity MDS instrument with the following conditions:

[0289] • Column set: 2 x PolarGel M columns (300 x 7.5 mm)

[0290] • Injection volume: 100 pl

[0291] • Eluent: DMAc + 0.9% LiCl

[0292] • Detector: Refractive Index (RI) • Columns temperature: 40 °C

[0293] • Detectors temperature: 40 °C

[0294] • Flow rate: 1.0 ml / min

[0295] • Calibration to evaluate molecular weight with polystyrene standards.

[0296] Aqueous Compositions

[0297] The rheology of the aqueous compositions are measured to determine the Rheometer thixotropy, Viscometer viscosity, and Rheometer flow curves of the composition:

[0298] • Rheometer Thixotropy: To evaluate the thixotropic nature of the aqueous compositions, different levels of shear gradient are successively applied, all carried out at 25 °C. In detail, a first phase consists of leaving the product almost at rest to assess its average viscosity by applying very low shear of the order of 0.01 s'1for 5 minutes, then suddenly subjecting the product to intense shear (1000 s'1) for 1 minute. At the end of the specified time, the product is returned to a low shear equivalent to the first phase (0.01 s'1) for about 30 minutes. The thixotropic character of a product is visible during this last step: the product will take a greater or lesser time to regain the level of viscosity obtained during the first phase at 0.01 s'1.

[0299] • Rheometer Flow curve: The determination of the flow curve is done with a fresh sample of the aqueous composition. A hysteresis flow curve is carried out at 25 °C between a shear of 0.01 s'1to 1000 s'1during a period of 200 seconds with a logarithmic ramp of multiply by 10 every 20 seconds, followed by a shear from 1000 s'1to 0.01 s'1also for a period of 200 seconds with a logarithmic ramp divided by 10 every 20 seconds. This measurement makes it possible to know the level of viscosity and therefore the mechanical stress necessary to make the product flow under different shear intensities. An Anton Paar Rheometer MCR 302e is used, with a measuring geometries of parallel plate of 50mm. The viscosity of the samples is measured in function of the shear rate from 0.01 to 1000 s-1. A stabilization step of 30 seconds at 0.01 s-1 was used before the measurement. The results are presented with a graph of viscosity versus shear.

[0300] • Viscometer Viscosity: The viscometer measures fluid viscosity at given shear rates. The Viscometer rotates a sensing element in a fluid and measures the torque necessary to overcome the viscous resistance to the induced movement. The Torque measured is proportional to the viscosity of the fluid. The immersed element is called a spindle. Samples are measured using a ROTAVISC lo-vi Complete viscometer with a #3 spindle. The samples are measured with the following conditions: 60rpm; 60s stabilization before the measurement.

[0301] Coated Non-Woven Fibrous Mat

[0302] The following tests may be carried out on the coated non-woven fibrous mat:

[0303] • Air permeability. The air permeability test is carried out in accordance with ASTM D737.

[0304] • Machine direction tensile strength. The Machine Direction Tensile Strength is carried out with sample dimensions of 300 x 50 mm.

[0305] • Cobb test. The Cobb value can be determined in accordance with European Standard EN20535 (as adapted to non-woven fibrous mats). The average Cobb value can be obtained by performing the Cobb test at least twice, and calculating the mean value.

[0306] Gypsum Board

[0307] The adhesion (dolly test) of the coated non-woven fibrous mat when incorporated into a gypsum board is carried out in accordance with ASTM D4541.

[0308] Preparation of the aqueous compositions

[0309] Examples 1 and 2

[0310] Two aqueous compositions are prepared as follows: according to the invention not according to the invention The components are mixed in order with a high-speed disc disperser, for example, a Dispermat CN30 (Brant Industrie). The thixotropic behaviour, Viscometer viscosity and Rheometer flow curves for the aqueous compositions are determined as set out above in the Test Methods section.

[0311] Example 3 Preparation of the Coated Non-Woven Fibrous Mats

[0312] A commercially available non-woven fibrous precursor mat (U 85 / 1) is obtained from Adfors.

[0313] The precursor mat is a wet laid glass veil.

[0314] The technical characteristics of the precursor mat are:

[0315] Tolerances:

[0316] Width: ± 3 mm for precursor mat with trimmed edges.

[0317] ± 12 mm for precursor mat with untrimmed edges.

[0318] Coating the Precursor Mat using A Knife Over Roll Process

[0319] The precursor mat is coated with the aqueous compositions of Examples 1 and 2.

[0320] The knife-over-roll coating technique is where a knife blade is suspended above a roller and does not touch the substrate (i.e. the precursor mat) directly. In this configuration, the coating layer thickness is controlled by a gap between the substrate and the knife by setting the gap between the roller and the blade.

[0321] The coated precursor mats are dried using an oven to form Coated Non-Woven Fibrous Mat 1 (using the aqueous composition of Example 1) and Coated Non-Woven Fibrous Mat 2 (using the aqueous composition of Example 2). The veil was dried to remove sufficient water such that the coated non-woven fibrous mats exhibited the desired performance.

[0322] The composition of the coated non-woven fibrous veil is: gsm = grams per square meter according to the invention not according to the invention

[0323] Figure 1 is a representative thixotropy curve for the aqueous composition of the present invention defined above in Example 1. The thixotropic nature of the aqueous composition is determined using the Thixotropy test described above. As can be seen, the aqueous composition is clearly thixotropic as it has a viscosity in the range of about 8 x 106mPa.s and about 1.2 x 107mPa.s at a temperature of about 25 °C and a shear rate of 0.01 s'1. The viscosity then reduces to a viscosity in the range of about 400 mPa.s and about 1000 mPa.s when the aqueous composition is exposed to a shear rate of 1000 s'1for 30 seconds. Then, after the high shear exposure has ceased and after a period of about 10 seconds has lapsed, the viscosity of the aqueous composition increases once again to a range of about 1.5 x 105mPa.s and about 2.5 x 105mPa.s.

[0324] Figure 2 shows the average Cobb values for (a) the coated non-woven veil of the present invention, and (b) the comparative coated non-woven veil. The compositions of the coated non-woven veils are as described in the table above. The average Cobb value for the coated non-woven veil of the present invention is significantly lower than that of average Cobb value the comparative coated non-woven veil. In this respect, the lower the Cobb value the better as this demonstrates that the coated non-woven fibrous of the invention mat has a greater hydrophobicity to water than the comparative coated non-woven veil.

[0325] Figure 3 shows the average dolly adhesion values for (a) the coated non-woven veil of the present invention when adhered to a gypsum core, and (b) the comparative coated non-woven veil when adhered to a gypsum core. The compositions of the coated non-woven veils are as described in the table above. The average adhesion value of the coated non-woven veil of the invention is significantly higher than the average adhesion value of the comparative coated non-woven veil. In this respect, the higher the adhesion value the better as it demonstrates that the coated non-woven veil of the invention is strongly adhered.

[0326] Example 4

[0327] Recipe 1 (according to the invention) and Recipe 2 and 3 (comparative) Two aqueous compositions are prepared with the following conditions: according to the invention i not according to the invention

[0328] The components are mixed in the same order as for Example 1 and 2, with a high-speed disc disperser, for example, a Dispermat CN30 (Brant Industrie).

[0329] The thixotropic behaviour, Viscometer viscosity and Rheometer flow curves for the aqueous compositions are determined as set out above in the Test Methods section. Viscometer results

[0330] The Viscometer viscosity of Recipe 2 (according to US20230109479A1) is confirmed to be 592 cP. In contrast, the Viscometer viscosity of Recipe 1 (according to the invention) under the same conditions is more than 40 times greater as it has a viscometer viscosity of 24750 cP.

[0331] It is clear that the Viscometer viscosity of the Recipe 2 corresponds to a fluid aqueous composition that is not suitable for use with knife over roll coating equipment. The Viscometer viscosity of Recipe 3 (comparative) is also not suitable for use with a knife- over-roll coating process as it is below the desirable minimum of 10000 cP.

[0332] Rheometer Flow curve results

[0333] The Rheometer flow curve of Recipe 2 (according to US20230109479A1) shows that at low shear (at 25°C and 0.01 s-1), the viscosity is very fluid (at 620 mPa.s) whereas the viscosity of Recipe 1 of the invention at 25°C and 0.01 s-1 is very high (above 5.106mPa). Recipe 1 therefore is appropriate for use in the knife-over-roll technique as its viscosity is well above the desirable minimum viscosity under low shear of 2 x 106mPa.s at a temperature of about 25 °C and a shear rate of about 0.01 s'1. Recipe 2, however, is not suitable for use in the knife- over-roll technique.

[0334] At high shear, Recipe 1 exhibits shear thinning but still maintains a suitable viscosity such that a non-woven mat would be coated asymmetrically in a knife-over-roll process. In contrast, the viscosity of Recipe 2 reduces even further and becomes even more fluid.

[0335] Figure 4 is a representative flow curve for the aqueous composition of the present invention. Recipe 1 is according to the invention and Recipe 2 is a comparative example. The flow curve of the aqueous composition is determined using the flow curve test described above. As can be seen, the aqueous composition of Recipe 1 has a viscosity in the range of about 5 x 106mPa.s and about 1.2 x 107mPa.s at a temperature of about 25 °C and a shear rate of 0.01 s'1. The viscosity then reduces to a viscosity in the range of about 400 mPa.s and about 1000 mPa.s at a temperature of about 25 °C and a shear rate of 1000 s'1. On the contrary, the aqueous composition of Recipe 2 has a viscosity in the range of about 140000 mPa.s at a temperature of about 25 °C and a shear rate of 0.01 s'1. This viscosity is too low to allow a possible use in a knife-over-roll coating device.

Claims

Claims1. An aqueous composition for coating a non-woven fibrous mat, the composition comprising:• an aqueous hydrophobic binder;• a hydrophobically modified cellulose;• an inorganic filler;• a dispersant; and• water; wherein the aqueous hydrophobic binder is a copolymer of: i) a monomer unit selected from vinyl versatate, an isomer of vinyl versatate, or a mixture thereof; and ii) at least one monomer unit selected from (meth)acrylic acid, or (methyl)acrylate.

2. An aqueous composition according to claim 1, wherein the inorganic filler is selected from calcium carbonate, magnesium carbonate, talc, aluminum trihydrate, vermiculite, antimony oxide, titanium dioxide, aluminium trihydrate, a clay, or a combination thereof.

3. An aqueous composition according to claim 1 or claim 2, wherein the dispersant is selected from polyphosphate salts, polycarboxylate salts, poly(meth)acrylate salts, or citrate salts, optionally sodium polyphosphate.

4. An aqueous composition according to any one of the preceding claims, wherein the hydrophobically modified cellulose has a weight average molecular weight (Mw) in the range of about 500000 to about 1000000 g / mole as measured by gel permeation chromatography.5 An aqueous composition according to claim 4, wherein the hydrophobically modified cellulose is selected from hydrophobically modified hydroxymethylcellulose, hydrophobically modified hydroxyethylcellulose, hydrophobically modified hydroxypropylcellulose, hydrophobically modified methylhydroxyethylcellulose, hydrophobically modified methylhydroxypropylcellulose, or a combination thereof.

6. An aqueous composition according to any one of the preceding claims, further comprising a biocide.

7. An aqueous composition according to any one of the preceding claims, wherein the aqueous composition has a viscosity in the range of about 2 x 106mPa.s to about 3 x 107mPa.s at a temperature of about 25 °C and a shear rate of 0.01 s’1, and a viscosity in the range of about 300 mPa.s to about 1200 mPa.s at a temperature of about 25 °C and a shear rate of 1000 s’1.

8. A coated non-woven fibrous mat, the coated non-woven fibrous mat comprising:(a) a precursor mat comprising:• a non-woven web of fibers comprising glass fibers, and• a first binder; and(b) a hydrophobic coating which coats the precursor mat, wherein the hydrophobic coating is formed from the aqueous composition according to any one of the preceding claims.

9. A coated non-woven fibrous mat according to claim 8, wherein the coated non-woven fibrous mat has an average Cobb value of below 25 g / m2when measured in accordance with EN20535 as adapted for non-woven fibrous mats.

10. A method for manufacturing a coated non-woven fibrous mat comprising the steps of:(v) providing a precursor mat comprising glass fibers and a first binder;(vi) depositing the aqueous composition according to any one of claims 1 to 7 on the precursor mat;(vii) coating the precursor mat with the aqueous composition with a knife-over-roll technique, wherein as the precursor mat and aqueous composition pass through a predetermined gap between the knife and the roll, the knife contacts the aqueous composition, the aqueous composition exhibits shear thinning on contact with the knife, andthe precursor mat is coated with the aqueous composition; and (viii) drying the coated precursor mat to form the coated non-woven fibrous mat.

11. A method according to claim 10, wherein the precursor mat is prepared in a method comprising the steps of:(i) providing an aqueous mixture comprising glass fibers, and a first binder;(ii) forming a dispersion of the aqueous mixture;(iii) depositing the aqueous dispersion to form a wetlaid web of glass fibers, and first binder;(iv) drying the wetlaid web of glass fibers, and first binder to form the precursor mat.

12. A method according to claim 10, wherein the precursor mat is 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 first binder to the wetlaid web of glass fibers, to form a wetlaid web of glass fibers, and first binder;(iv) drying the wetlaid web of glass fibers, and first binder to form the precursor mat.

13. A construction board comprising: a first surface and a second surface opposite the first surface, a coated non-woven fibrous mat adhered to the first surface, the second surface or both the first and second surfaces, and wherein the coated non-woven fibrous mat is according to claim 8 or claim 9.

14. A construction board according to claim 13, further comprising a layer of ink as the outermost layer of the first surface, the second surface or both the first and second surfaces of the construction board.

15. A construction board according to claim 13 or claim 14, wherein the construction board is selected from the group consisting of a ceiling tile, gypsum board, building panel, isolation panel, and floorboard, optionally a gypsum board.

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