Application of aqueous dispersion of magnesium compound in functional finishing of textiles

Abstract

The present invention provides compositions and aqueous dispersions comprising magnesium oxide as the sole active agent or in combination with ammonium phosphate / ammonium polyphosphate to impart antibacterial and / or antiviral properties to textile products. The invention further provides methods for preparing the compositions and aqueous dispersions, as well as methods of using the compositions and aqueous dispersions for textile finishing.

Description

[0001] This application is a divisional application of patent application No. 202180026815.5 with the title "Use of aqueous dispersion of magnesium compound in functional finishing of textiles" and filed on April 01, 2021. TECHNICAL FIELD

[0002] The present invention relates to an aqueous dispersion comprising a magnesium compound, in particular a specific grade of magnesium oxide, either alone or in combination with ammonium phosphate or polyammonium phosphate. The dispersions provided are used in the field of functional finishing of textiles, in particular as antiviral and antibacterial textile finishing agents. BACKGROUND

[0003] Commercially used polymers contain additives to improve processability and to change the properties of the polymer. For example, textile products contain flame retardants to improve fire resistance and also biocides to eliminate or at least inhibit the deposition and growth of microorganisms on or in the fabric. Different techniques are used to incorporate the additives into the finished textile product. For example, the additives can be formulated into a solution, emulsion or aqueous suspension, and the fabric is then soaked in the solution, squeezed to remove excess liquid and then dried.

[0004] Biocides commonly used in the textile industry include organic copper compounds, organic tin compounds and chlorinated phenols (https: / / www.fibre2fashion.com / industry-article / 27 / biocides-in-textile). As discussed by Uddin (International Journal of Textile Science, 2014 3(1A) 15:20), silver-based microbial agents and metal-based inorganic compounds such as zinc oxide, zinc and copper salts have also been tested in fabrics.

[0005] Other examples can be found in the patent literature. CA 1334273 describes a microbial killing composition for textiles based on certain phosphate esters. In JP 10088482, a polyester fabric is treated with an antimicrobial agent consisting of an alkyl phosphate ester (as a quaternary ammonium salt) and a diisocyanate. In CN 105297401, cotton fabric is subjected to antimicrobial finishing by soaking in ammonium sulfate and ethoxylated alkyl amine.

[0006] There is a great interest in the development of textile finishing agents with antibacterial and antiviral activity. Such finishing agents are particularly valuable because they can assist in preventing the spread of infectious diseases and enable textile materials to be used in hospitals without the need for frequent sterilization. SUMMARY

[0007] Inorganic magnesium compounds with low solubility in water, particularly specific grades of magnesium oxide (magnesia, MgO) and / or magnesium hydroxide, are available in various grades on the market, designed for diverse industrial needs. Magnesium oxide is used in the plastics industry (such as as an additive in rubber and resins), the pharmaceutical industry (such as for the production of tablet granules), and the steel industry (for the manufacture of steel plates for transformers).

[0008] The inventors have tested the activity of certain grades of MgO in textile products and found that MgO itself exhibits antibacterial, antiviral and slight antimicrobial effects in these products (such as polyester fabrics), and these effects are strongly enhanced when MgO is mixed with ammonium polyphosphate (APP), such as aluminum ammonium polyphosphate.

[0009] Both MgO and APP are water-insoluble powders. The inventors have prepared a co-formulation that disperses MgO and APP in water with the aid of conventional additives (such as dispersants and thickeners) in the presence of an adhesive (to adhere the active compound to the fabric). The aqueous MgO / APP co-formulation can be used to deliver the active ingredient to fabrics using conventional techniques employed in the textile industry, such as filling, coating, and soaking.

[0010] Therefore, one aspect of the present invention is a composition comprising magnesium oxide, a surfactant, and a thickener.

[0011] In some embodiments, the magnesium oxide according to the invention is characterized by having d 10 The range is 0.5 to 1.5 μm, d 50 The range is from 1.5 μm to 6.0 μm and d 90 A particle size distribution ranging from 5.0 μm to 45.0 μm, wherein the magnesium oxide is further characterized by having:

[0012] a) The range is 5.0 to 25.0m 2 / gr surface area,

[0013] b) Loss on ignition (LOI) ranging from 0.2% to 8.0%,

[0014] c) Bulk density ranging from 0.25 to 0.50 gr / ml, and

[0015] d) Citric acid activity in the range of 25 to 200 seconds (CAA 40).

[0016] In other embodiments, the magnesium oxide according to the invention is characterized by having: d 10 The range is 0.5 to 1.5 μm, d 50 The range is 1.5 to 6.0 μm and d90 particle size distribution ranging from 5.0 to 45 pm, surface area ranging from 5.0 to 25.0 m 2 / gr, LOI ranging from 0.2 to 5.0%, bulk density ranging from 0.30 to 0.50 gr / ml, citric acid activity (40) ranging from 80 to 200 seconds.

[0017] In a further embodiment, the magnesium oxide according to the present application is characterized by having: d 10 ranging from 0.8 to 1.5 pm, d 50 ranging from 2.5 to 6.0 pm and d 90 particle size distribution ranging from 10.0 to 45 pm, surface area ranging from 5.0 to 15.0 m 2 / gr, LOI ranging from 2.0 to 8.0%, bulk density ranging from 0.25 to 0.35 gr / ml, citric acid activity (40) ranging from 100 to 200 seconds.

[0018] In a further embodiment, the magnesium oxide according to the present application is characterized by having: d 10 ranging from 1.0 to 1.5 pm, d 50 ranging from 2.5 to 6.0 pm and d 90 particle size distribution ranging from 10.0 to 45.0 pm, surface area ranging from 5.0 to 10.0 m 2 / gr, LOI ranging from 0.2 to 6.0%, bulk density ranging from 0.3 to 0.5 gr / ml, citric acid activity (40) ranging from 100 to 200 seconds.

[0019] In another aspect thereof, the present application provides an antiviral and / or antibacterial textile finishing aqueous dispersion comprising the composition as defined herein, and optionally comprising a binder. In other words, the present application provides an antiviral and / or antibacterial textile finishing aqueous dispersion comprising magnesium oxide, a surfactant, a thickening agent, and optionally a binder. The aqueous dispersion as defined herein facilitates textile finishing and imparts antiviral and / or antibacterial properties to the textile product.

[0020] In some embodiments, the textile finishing aqueous dispersion according to the present application comprises:

[0021] 67 to 90% by weight of water;

[0022] 2 to 20% by weight of MgO;

[0023] 0.5 to 4% by weight of surfactant; and

[0024] 0.1 to 0.5% by weight of thickening agent.

[0025] In other embodiments, the textile finishing aqueous dispersion according to the present application comprises:

[0026] 67 to 90 wt% water;

[0027] 2 to 20 wt% MgO;

[0028] 0.5 to 4 wt% surfactant;

[0029] 0.1 to 0.5 wt% thickener; and

[0030] 1.5 to 15 wt% binder.

[0031] In further embodiments, the textile finishing aqueous dispersion according to the present application further comprises ammonium phosphate or ammonium polyphosphate, and optionally a binder.

[0032] In certain embodiments, the ammonium polyphosphate according to the present application is aluminum ammonium polyphosphate.

[0033] In other embodiments, the textile finishing aqueous dispersion according to the present application comprises:

[0034] 37 to 94 wt% water;

[0035] 5 to 20 wt% MgO;

[0036] 0.5 to 4 wt% aluminum ammonium polyphosphate;

[0037] 0.5 to 4 wt% surfactant; and

[0038] 0.1 to 0.5 wt% thickener.

[0039] In still further embodiments, the textile finishing aqueous dispersion according to the present application comprises:

[0040] 37 to 94 wt% water;

[0041] 5 to 20 wt% MgO;

[0042] 0.5 to 4 wt% aluminum ammonium polyphosphate;

[0043] 0.5 to 4 wt% surfactant;

[0044] 0.1 to 0.5 wt% thickener; and

[0045] 1.5 to 15 wt% binder.

[0046] In some embodiments, the surfactant according to the present application is an anionic surfactant or a non-ionic surfactant. In other embodiments, the thickening agent according to the present application is a cellulose derivative or an expandable synthetic polymer. In further embodiments, the binder according to the present application is an acrylic, a polyurethane or a PVC binder.

[0047] In a further aspect thereof, the present application provides a method of finishing or treating a textile product with an antiviral and / or antibacterial aqueous dispersion as defined herein, wherein a binder is present in the dispersion.

[0048] In some embodiments, the method according to the present application imparts to the textile product a virus-inhibiting or antiviral property. In certain embodiments, the method according to the present application imparts to the textile product a virus-inhibiting or antiviral property against a virus of the Coronaviridae family.

[0049] In further embodiments, the method according to the present application imparts to the textile product a bacteriostatic or antibacterial property. In certain embodiments, the method according to the present application imparts to the textile product a bacteriostatic or antibacterial property against a bacterium associated with a hospital infection. In still further embodiments, the hospital infection according to the present application is associated with Staphylococcus aureus or Escherichia coli or a combination thereof.

[0050] The present application further provides the use of magnesium oxide as at least one of a virus-inhibiting textile finish, an antiviral textile finish, a bacteriostatic textile finish or an antibacterial textile finish.

[0051] The present application still further provides the use of magnesium oxide in combination with ammonium phosphate or polyphosphate ammonium as at least one of a virus-inhibiting textile finish, an antiviral textile finish, a bacteriostatic textile finish or an antibacterial textile finish.

[0052] By another of its aspects, the present application provides a textile product coated with an antiviral or antibacterial finish comprising magnesium oxide, wherein the amount of magnesium oxide is at least 2%, for example up to 15% or 20%, relative to the weight of the textile product.

[0053] The present application still further provides a textile product coated with an antiviral or antibacterial finish comprising a combination of magnesium oxide and ammonium phosphate or polyphosphate ammonium, wherein the amount of magnesium oxide is at least 2%, for example up to 15% or 20%, and the amount of ammonium phosphate or polyphosphate ammonium is at least 0.5%, for example up to 2%, relative to the weight of the textile product.

[0054] In some embodiments, the textile product according to the present application is a medical textile product, a facial mask or a fabric filter. BRIEF DESCRIPTION OF DRAWINGS

[0055] Figures 1A-1B The figure shows the temperature reaching a maximum of 600℃. Figure 1A or reach 900℃ Figure 1B The weight loss (%) of HA4 grade MgO samples during TGA testing within the temperature range.

[0056] Figures 2A-2B The figure shows virus counts measured at different time points in an AATCC test using 100% polypropylene 30GSM spunbond nonwoven fabric coated with an aqueous dispersion containing HA4 grade MgO (“MgO HA4”) or containing HA4 grade MgO and APP (“MgO HA4+”). An aqueous dispersion of AG” was tested within the first 4 hours. Figure 2A ) or within the entire test duration ( Figure 2B Inoculate with E. coli bacteriophage MS2. The “control” refers to uncoated fabric.

[0057] Figures 3A-3B The figure shows bacterial counts measured at different time points in an AATCC test using spunbond nonwoven 100% polypropylene 30GSM fabric coated with an aqueous dispersion containing HA4 grade MgO (“MgO HA4”) or containing HA4 grade MgO and APP (“MgO-HA4+”). An aqueous dispersion of AG” was tested within the first 6 hours. Figure 3A ) or within the entire test duration ( Figure 3B Inoculation with Staphylococcus aureus. The "control" refers to uncoated fabric.

[0058] Figures 4A-4C The figure shows bacterial counts measured at specified time points in an AATCC test performed on polyamide-Lycra fabric samples coated with an HA4 grade MgO aqueous dispersion in the presence of Staphylococcus aureus. The aqueous dispersion contained AC-178 (…). Figure 4A AC-2403 Figure 4B ) or AC-75032 ( Figure 4C (), after 10, 20, 35 or 50 washing cycles. "Control" refers to uncoated fabric. Detailed Implementation

[0059] In its most general form, magnesium oxide is prepared by calcining magnesium hydroxide. The temperature distribution within the calcining kiln affects the properties and activity of the resulting magnesium oxide.

[0060] A magnesium oxide grade suitable for use in the present application is selected to meet a set of criteria, for example:

[0061] - a particle size distribution (PSD) characterised by d 10 , d 50 and d 90 values such that d 10 ≤ 1.5 pm (e.g. 0.5 to 1.5 pm, 0.5 to 1.0 pm or 0.8 to 1.3 pm), 1.5 pm ≤ d 50 ≤ 6.0 pm (e.g. 1.5 to 5.0 pm) and 5.0 pm ≤ d 90 ≤ 45.0 pm (e.g. 8.0 pm ≤ d 90 ≤ 45.0 pm or 5.0 pm ≤ d 90 ≤ 30 pm) (measured by laser diffraction).

[0062] - a specific surface area greater than 5.0 m 2 / gr, preferably 5.0 to 25.0 m 2 / gr., more preferably 5.0 to 15.0 m 2 / gr, more preferably 5.0 to 10 m 2 / gr or 5.0 to 9 m 2 / gr (measured by the BET method).

[0063] - a citric acid activity (CAA 40) in the range 25 to 200 seconds, preferably 80 to 200 seconds, e.g. 150 to 200 seconds.

[0064] - a loss on ignition (LOI, a measure of magnesium hydroxide residue) in the range 0.2 to 8.0 wt%, e.g. 4.0 to 8.0 wt%, preferably 0.2 to 3.0 wt% or 0.2 to 1.0 wt%.

[0065] - a bulk density in the range 0.25 to 0.50 gr / ml, e.g. 0.30 to 0.40 gr / ml or 0.25 to 0.35 gr / ml.

[0066] For example, for a particular magnesium oxide (HA4 grade) preparation tested (TGA performed up to a temperature of 600°C), the magnesium hydroxide residue (TGA) was 0.724%, as shown in Table 1 below; whereas for a further HA4 grade magnesium oxide preparation, the magnesium hydroxide residue (TGA) was 2.073%, as shown in Table 2 below (involving TGA performed up to a temperature of 900°C). Figure 1A Figure 1B For example, for a particular magnesium oxide (HA4 grade) preparation tested (TGA performed up to a temperature of 600°C), the magnesium hydroxide residue (TGA) was 0.724%, as shown in Table 1 below; whereas for a further HA4 grade magnesium oxide preparation, the magnesium hydroxide residue (TGA) was 2.073%, as shown in Table 2 below (involving TGA performed up to a temperature of 900°C).

[0067] ​Grades meeting the above properties are commercially available (e.g. MgO HA4 grade, MgO SIG-SC grade or MgO SIG-S grade from ICL-IP). An illustrative method of preparation of MgO used in the present application is provided in the experimental section below, which is based on milling (dry milling) of MgO products obtained by calcination of magnesium hydroxide at temperatures ranging from 600 to 950 °C. Alternatively, the preparation of MgO used in the framework of the present application can be based on wet milling of magnesium hydroxide prior to the calcination step described above. The magnesium hydroxide itself can be obtained by hydration of the thermal decomposition product of magnesium chloride (Aman process), or by a precipitation reaction (i.e. between magnesium chloride and a basic agent such as sodium hydroxide, calcium hydroxide or ammonium hydroxide, etc.).

[0068] The physical properties of the MgO grades suitable for use in the present application can be determined based on methods well known in the art, for example as detailed in the examples below.

[0069] In one of its aspects, the present application provides an antimicrobial and / or antiviral textile finishing aqueous dispersion comprising magnesium oxide, a surfactant and a thickening agent, and optionally a binder.

[0070] To prepare the composition of the present application, the magnesium oxide powder having the features described herein, the surfactant and the thickening agent are mixed by any method known to the person skilled in the art. Preferred surfactants and thickening agents are described below.

[0071] To prepare the aqueous dispersion of MgO, the MgO powder (such as MgO HA4 grade from ICL-IP) is mixed with water in the presence of one or more surfactants (such as a dispersant and optionally a wetting agent) with the help of a dissolver stirrer / disperser running at 300 to 600 revolutions per minute (rpm) on a laboratory scale. Then, the thickening agent is added. The aqueous dispersion as defined herein can further comprise a binder, such as an acrylic binder, which is the last to be added to the dispersion.

[0072] A stable dispersion of MgO in water is formed, wherein the content of MgO is not less than 2 wt.%, for example from 2 to 20 wt.%, based on the total weight of the MgO dispersion. If a binder is present, the concentration of the binder is typically from 1.5% to 15%. The concentration of the surfactant (e.g. dispersant) is from 0.5 to 4%. The concentration of the thickening agent is from 0.1 to 0.5%. When a wetting agent is added, the concentration of the wetting agent is from 0 to 0.4% (up to 0.4%). The MgO dispersion can optionally further comprise a softener and additional textile additives known in the art.

[0073] Thus, a preferred aqueous MgO dispersion of the present application comprises (in weight percent based on the total weight of the aqueous MgO dispersion):

[0074] 67 to 90 wt% water, such as 70 to 80 wt%;

[0075] 2 to 20 wt% MgO, such as 9.9 to 13.4 wt%;

[0076] 0.5 to 4 wt% surfactant (e.g. dispersant), such as 0.9 to 1.5 wt%;

[0077] 0.1 to 0.5 wt% thickening agent, such as 0.3 to 0.5 wt%; and

[0078] 1.5% to 15 wt% binder, such as 9 to 15 wt%.

[0079] It will be appreciated that the term “aqueous dispersion” (used interchangeably with “aqueous suspension”) for the purposes of the present application refers to a dispersion of the solids (powders) and additives described herein in an aqueous carrier. Aqueous dispersions are typically characterised by a solids concentration in the range of 20 wt% to 40 wt% of the total weight of the aqueous dispersion / suspension. The solids content includes all dispersion components other than the aqueous carrier, such as the MgO powder, the APP powder (i.e. ammonium phosphate or polyphosphate, if present), the binder, the surfactant (e.g. dispersant) and the like.

[0080] As detailed herein, the inventors have found that the effect of MgO is strongly enhanced when mixed with ammonium polyphosphate (APP), for example an ammonium polyphosphate salt, for application to a fabric. Without wishing to be bound by theory, the enhanced antibacterial and antiviral properties arise from, amongst other sources, the uniform textile coverage provided by the addition of APP to the aqueous dispersion defined herein.

[0081] The present application therefore further provides an antibacterial and / or antiviral textile finishing aqueous dispersion as described herein, further comprising ammonium phosphate or polyphosphate.

[0082] The ammonium phosphate or polyphosphate suitable for use according to the present application is preferably a polyvalent metal complex of ammonium polyphosphate as described in WO 2016 / 199145, in particular the reaction product of: phosphoric acid (superphosphoric) in concentrated form; a source of polyvalent metal (e.g. an aluminium compound such as AI(OH)3); and ammonium hydroxide, which is recoverable as a white, free-flowing, fine powder. The above reaction product, i.e. ammonium polyphosphate aluminium or superphosphoric aluminium ammonium, is in amorphous form, with a phosphorus content of up to 60 wt% or more, for example 70 to 80 wt%; a nitrogen content of over 8 wt%, for example 9 to 10 wt%; an Al content of over 5 wt%, for example 6 to 8 wt%; and a water content of ~5 to 10 wt%. A suitable commercially available product is SUPERPHOS® from ICL-IP. 3- + The ammonium phosphate or polyphosphate suitable for use according to the present application is preferably a polyvalent metal complex of ammonium polyphosphate as described in WO 2016 / 199145, in particular the reaction product of: phosphoric acid (superphosphoric) in concentrated form; a source of polyvalent metal (e.g. an aluminium compound such as AI(OH)3); and ammonium hydroxide, which is recoverable as a white, free-flowing, fine powder. The above reaction product, i.e. ammonium polyphosphate aluminium or superphosphoric aluminium ammonium, is in amorphous form, with a phosphorus content of up to 60 wt% or more, for example 70 to 80 wt%; a nitrogen content of over 8 wt%, for example 9 to 10 wt%; an Al content of over 5 wt%, for example 6 to 8 wt%; and a water content of ~5 to 10 wt%. A suitable commercially available product is SUPERPHOS® from ICL-IP.​ AG, having a particle size distribution of d 50 <5 microns, d 90 <15 microns, and d 99 <35 microns. The symbol APP is used herein to mean any ammonium phosphate / polyphosphate, including the polyvalent metal complexes exemplified and / or described above. Other phosphorus agents suitable for use according to the present application include mono-ammonium phosphate (MAP) or sodium pyrophosphate decahydrate (NAPP) without the necessity of performing multiple wash cycles.

[0083] In a particular embodiment, the MgO / APP co-dispersion defined herein comprises MgO and ammonium phosphate / polyphosphate, said ammonium phosphate / polyphosphate being AG (aluminum ammonium polyphosphate).

[0084] The MgO / APP co-formulation (interchangeably referred to as co-dispersion) according to the present application can be prepared by first separately formulating or dispersing each of the above-mentioned MgO and APP. The resulting separate MgO and APP dispersions are then combined into the MgO / APP co-formulation, i.e. in the form of a dispersion. The weight ratio of MgO:APP in the co-formulation is, for example, in the range of 5:1 up to 20:1, such as 10:1, 15:1, etc.

[0085] Alternatively, the MgO / APP co-formulation according to the present application can be prepared by co-suspending both water-insoluble solids in a single dispersion. Specifically, MgO powder (e.g., MgO HA4 grade from ICL-IP) is mixed with water in the presence of one or more surfactants (e.g., dispersants and optionally humectants) with the help of a dissolver agitator / disperser running at 300 to 600 revolutions per minute (rpm) on a laboratory scale. APP (e.g., AG from ICL-IP) is added gradually while continuing to agitate. The last ingredients added are (optional) binders (e.g., acrylic binders), thickeners, and optionally softening agents.

[0086] A stable dispersion / suspension of both MgO and APP in water is formed, wherein: the MgO content is not less than 5 wt.%, e.g., 5 to 20 wt.%, based on the total weight of the MgO / APP dispersion; the APP content is not less than 0.5 wt.%, e.g., 0.5 to 4 wt.%, based on the total weight of the MgO / APP dispersion. The concentration of the binders is 1.5 to 15%. The concentration of the surfactants (e.g., dispersants) is 0.5 to 4%. The concentration of the thickeners is 0.1 to 0.5%. When humectants are added, the concentration of the humectants is 0.1 to 0.5%, and furthermore the MgO / APP dispersion can optionally further comprise softening agents and additional textile additives known in the art. ​

[0087] Accordingly, the present application further provides an aqueous dispersion comprising:

[0088] 37 to 94 wt% water;

[0089] 5 to 20 wt% magnesium oxide;

[0090] 0.5 to 4 wt% ammonium phosphate / ammonium polyphosphate;

[0091] 0.5 to 4 wt% surfactant;

[0092] 0.1 to 0.5 wt% thickener; and

[0093] 1.5 to 15 wt% binder.

[0094] A preferred aqueous dispersion of the present application comprises (wt% based on the total weight of the MgO / APP aqueous dispersion):

[0095] 37 to 94 wt% water, for example 75 to 90 wt%;

[0096] 5 to 20 wt% MgO; for example 9.9 to 13 wt%;

[0097] 0.5 to 4 wt% ammonium polyphosphate, for example 0.9 to 2 wt%;

[0098] 0.5 to 4 wt% dispersant, for example 2 to 4 wt%;

[0099] 0.1 to 0.5 wt% thickener, for example 0.2 to 0.3 wt%; and

[0100] 1.5 to 15 wt% binder, for example 5 to 10 wt%.

[0101] The amount of binder varies depending on the application required as would be known to the skilled person. For example, when wash durability is required, a greater amount of binder will be used, in comparison, when fabric flexibility is required, a lesser amount of binder will be used.

[0102] An adhesive is required to adhere the magnesium oxide alone or in combination with the APP to the fabric, and thus the adhesive is part of the aqueous dispersion of the present invention (although it can be added just prior to applying the dispersion to the fabric). Representative examples of adhesives suitable for use in textiles are described in WO 2016 / 199145, including but not limited to acrylic, polyurethane, and PVC adhesives. Preferably, the adhesive used in the dispersions described herein is an acrylic. The acrylic monomer structural units of the acrylate resin can be selected from the group consisting of alkyl acrylates and alkyl methacrylates (alkyl esters of acrylic or methacrylic acid), wherein the alkyl group is preferably a C1-C5 alkyl group, such as methyl, ethyl, propyl (e.g., n-propyl), and butyl (e.g., n-butyl). The parent acid, acrylic or methacrylic acid, can also be used in small amounts to obtain the resin. The acrylic monomers can optionally be functionalized. Other examples include 2-phenoxyethyl acrylate, propoxylated (2) neopentyl glycol diacrylate, polyethylene glycol diacrylate, pentaerythritol triacrylate, 2-(2-ethoxyethoxy)ethyl acrylate. Commercially available acrylate resins containing 47 to 90% solids (e.g., AC-170, AC-178, AC-2403, AC-75032, etc.) are suitable.

[0103] The MgO or MgO / APP suspensions / dispersions described herein further comprise conventional additives. The main types of additives include:

[0104] one or more surfactants, i.e., dispersants, emulsifiers, wetting agents, combinations of dispersants / wetting agents (typically 0.5 to 4 wt% of each, e.g., 1.5 to 2.5 wt% of each);

[0105] one or more softening agents (typically 2 to 5 wt% of each, e.g., 2 to 3 wt% of each);

[0106] one or more rheology modifiers, i.e., thickeners (typically 0.1 to 0.5 wt% of each, e.g., 0.2 to 0.5 wt% of each).

[0107] The dispersant, wetting agent, or dispersant with necessary wetting properties is present in each of the individual MgO or MgO / APP suspensions described herein, i.e., at a concentration of 0.5 to 4.0 wt% (e.g., 1.5 to 2.5 wt%) in each, based on the total weight of the individual suspension. The dispersant can be an oligomer, polymer, or alkoxylate, as described in WO 2016 / 199145. For example, to make the MgO and MgO / APP suspensions, 2-4 wt% of a polymeric anionic surfactant (e.g., Sokalan® from Huntsman) can be used, based on the total weight of the MgO or MgO / APP aqueous dispersion. 2735) sodium polymethacrylate (e.g., Polyfloc® from Vanderbilt Minerals, LLC ) or sulfonate-based anionic surfactants (e.g., alkyl aryl sulfonates such as sodium diisopropyl naphthalene sulfonate). Polymer dispersants, e.g., nonionic acrylate copolymers (such as may be obtained in the form of an emulsion.

[0108] Rheological additives, such as thickening agents and anti-settling agents (e.g., water-soluble non-ionic polymers, such as commonly used hydroxyethyl cellulose (HEC) thickening agents) are typically added in each individual suspension / dispersion at a concentration of 0.1 to 0.5 wt.%, based on the total weight of the MgO or MgO / APP aqueous dispersion.

[0109] For example, to prepare the MgO and / or MgO / APP suspensions described herein, 0.1-0.5 wt.% of the thickening agent Cellosize QP 100MH (hydroxyethyl cellulose, high molecular weight HEC, Brookfield viscosity of 4400-6000 cp at 1%; particle size # mesh at least 98%) is used, based on the total weight of the MgO or MgO / APP aqueous dispersion. TM QP 100MH (hydroxyethyl cellulose, high molecular weight HEC, Brookfield viscosity of 4400-6000 cp at 1%; particle size # mesh at least 98%).

[0110] In each individual suspension, one or more softening agents (such as ethers and polyethylene glycol esters, ethoxylated products, paraffins, fatty or fatty acid condensates) can be further added to the inventive suspension at a concentration of 2 to 5 wt.%, based on the total weight of the MgO or MgO / APP aqueous dispersion, at the last stage of the preparation.

[0111] Other textile additives that can be used to prepare the inventive dispersions include, but are not limited to, antifoams, preservatives, dyes, pigments, and any mixture thereof.

[0112] As detailed herein, the present application further provides a method of finishing or treating a textile product with an antimicrobial and / or antiviral aqueous dispersion as defined herein, i.e., an aqueous dispersion comprising magnesium oxide, a surfactant, a thickening agent, a binder, and optionally ammonium phosphate / polyphosphate.

[0113] In particular, the present application relates to a method comprising finishing or treating a textile product with any one of the aqueous dispersions described and defined herein. The method of the present application is used to impart at least one of the properties of virus-inhibiting, antiviral, bacteriostatic, or antibacterial to the textile product.

[0114] Textiles can be treated or coated with the dispersions described herein in any industrially acceptable manner, such as padding (a wet finishing process involving impregnating the fabric with the formulation / dispersion, followed by pressing the fabric between heavy rollers to remove any excess formulation), coating, spraying (or other means of applying the water dispersion as defined herein to a textile or fabric) to have bacteriostatic, virustatic, antibacterial and / or antiviral properties. Impregnated coated fabrics are typically cured at about 120 to 160 °C for 3 to 6 minutes (a heat treatment process whose aim is to evaporate the solvent and to promote any necessary chemical reactions to fix the finish on the textile / fabric). Other types of fabrics and techniques for treating fabrics with water dispersions as defined herein are described in WO 2016 / 199145.

[0115] The application of the water dispersions as defined herein to a textile can be effected by the manufacturer of the textile, for example, at the dyeing or finishing stage of the textile, or at a later stage (for example, after the manufacture of the textile product is complete). The application of the water dispersions as defined herein to a textile is repeatable.

[0116] As explained below, the water dispersions of the present application are added to a textile product or fabric in an amount effective to reduce microbial growth or at least to prevent or inhibit it. The resulting textile product includes the additive collectively referred to by the term "add-on". The term "add-on" level (or percentage) refers to the total amount of additive (including non-active additive) loaded onto the treated textile product or fabric; it is calculated based on the difference in weight of the fabric (i.e. dry fabric) before and after treatment / curing. With the help of the MgO or MgO / APP water suspension / dispersion as defined herein, sufficient bacteriostatic or antibacterial, virustatic or antiviral properties are achieved at an "add-on" level of 2 to 20% of the weight of the fabric, i.e. a prevention of microbial growth or a reduction of 1-3 orders of magnitude in microbial culture as described in the experimental section below, respectively.

[0117] Thus, in a further aspect thereof, the present application provides a textile product treated or coated with an antiviral or antibacterial finish (water dispersion) comprising magnesium oxide, a surfactant, a binder, a thickener and optionally ammonium phosphate / ammonium polyphosphate, wherein the amount of MgO is at least 2%, for example up to 15% or 20%, and when APP is present, the amount of APP is at least 0.5%, for example up to 2%, based on the weight of the textile product. The total dry weight amount added to the fabric by the dispersion as defined herein is 2 to 20%.

[0118] The experimental work carried out to support the present application shows that MgO suspensions prepared as described herein, when applied to different types of fabric samples, show a bacteriostatic effect and a slight antibacterial effect, with a clear reduction of the bacterial count of about one order of magnitude after up to 24 hours compared to the starting point of the time.

[0119] In fabrics treated with dispersions comprising MgO (HA4 grade) and APP (AG) in combination, prepared as described herein, a strong antibacterial effect is shown, with a reduction of the bacterial count of about three (3) orders of magnitude after 24 hours compared to the starting point of the time (as shown, for example, in Example 1).

[0120] Furthermore, the inventors have demonstrated in Example 2 the antiviral properties of the prepared suspensions, and their application to fabrics as detailed herein, containing MgO alone or MgO mixed with APP. After application of the above suspensions, a reduction of the viral count of about three (3) orders of magnitude after 24 hours compared to the starting point of the time is shown, which demonstrates the antiviral properties.

[0121] Therefore, by another of its aspects, the present application provides the use of magnesium oxide as at least one of a virus-inhibiting textile finishing agent, an antiviral textile finishing agent, a bacteriostatic textile finishing agent or an antibacterial textile finishing agent.

[0122] By a further aspect, the present application provides the use of magnesium oxide in combination with ammonium phosphate or polyphosphate as at least one of a virus-inhibiting textile finishing agent, an antiviral textile finishing agent, a bacteriostatic textile finishing agent or an antibacterial textile finishing agent.

[0123] In particular, the present application relates to the use of magnesium oxide and optionally ammonium phosphate or polyphosphate (or a textile finishing aqueous dispersion comprising the above) as an antiviral textile finishing agent, and to the use of magnesium oxide and optionally ammonium phosphate or polyphosphate (or a textile finishing aqueous dispersion comprising the above) as an antibacterial textile finishing agent.

[0124] In other words, the present application provides a method for preventing or reducing the growth of bacteria or viruses on a textile product (or a portion thereof), said method comprising finishing or treating said textile product with an antiviral and / or antibacterial aqueous dispersion, said aqueous dispersion comprising magnesium oxide, a surfactant, a thickening agent, a binder, and optionally ammonium phosphate or polyphosphate.

[0125] ​Accordingly, the present application further provides a method of imparting a virus-inhibiting or antiviral property, a bacteria-inhibiting or antibacterial property to a textile product, the method comprising finishing or treating the textile product with an aqueous dispersion comprising magnesium oxide, a surfactant, a thickening agent, a binder, and optionally ammonium phosphate or polyphosphate.

[0126] As shown in the following examples, textile treated with the aqueous dispersion, either containing MgO alone or containing MgO mixed with APP, showed antibacterial and antiviral effects, where the textile was challenged (or inoculated) with Staphylococcus aureus, Escherichia coli phage MS2, and Escherichia coli.

[0127] The microorganisms known in the art are affected by the microorganism or combinations thereof. The present application relates to any microorganism, including but not limited to: viruses, such as viruses of the Coronaviridae family; and bacteria, such as Escherichia coli or bacteria associated with hospital infections, such as but not limited to Staphylococcus aureus (e.g., methicillin-resistant Staphylococcus aureus) and Pseudomonas aeruginosa. The present application can help to inhibit the growth of other microorganisms, such as archaea, algae, fungi (such as yeasts and molds), protozoa, and combinations thereof.

[0128] The term "reducing the growth of microorganisms" as used herein refers to slowing the rate of reproduction, or stopping the reproduction, or eliminating the viable microorganism cells, in a proportion of, for example, about 1, 10, 15, 20, 30, 40, 50% or more up to 100% compared to the untreated textile article.

[0129] The antibacterial and / or antiviral properties (and virus-inhibiting or bacteria-inhibiting properties) of the aqueous dispersion of the present application can be determined by any method known in the art, such as by performing the AATCC 100 test method for textile testing. The AATCC 100 test method evaluates the antibacterial properties of a textile during a 24-hour contact period (which can be extended), quantifying the properties of biostatic (growth inhibition) or biocidal (killing of microorganisms). The test method consists of sample preparation, sterilization, inoculation, incubation, washing / shaking out, and counting.

[0130] The finishing of a textile as defined herein relates to imparting antiviral and / or antibacterial properties to a textile, including virus-inhibiting and bacteria-inhibiting properties, respectively. The term "biocide" known in the art refers to a substance that kills microorganisms and their spores. Depending on the type of microorganism affected, a biocide can be further defined as a bactericide (or antibacterial agent), a fungicide (antifungal agent), an antiviral agent, an algicide, and the like. The general term "biostatic" refers to a substance that prevents the growth (reproduction) of microorganisms and their spores, including bacteriostatic substances (relating to bacteria), virus-inhibiting substances (relating to viruses), fungistatic substances, and algistatic substances.

[0131] As shown in the following examples, the aqueous dispersion of the present application comprising MgO alone or in combination with APP (MgO / APP) is suitable for use in a variety of textile (fabric or cloth), woven / knitted or non-woven fabrics (for example for the manufacture of filters, such as air conditioning filters), the above being natural, synthetic or a mixture thereof, for example consisting of fibers selected from the group consisting of wool, silk, cotton, nylon, polypropylene, flax, hemp, ramie, jute, acetate, lyocell, acrylic, polyolefin, polyamide, polylactic acid, polyester, rayon, viscose, spandex (also known as elastane, such as polyamide-Lycra fibers), metal composites, ceramic fibers, glass fibers, carbon fibers or carbonized composites and any combination of the above. Exemplary textiles are woven 12% nylon 66, 88% cotton 170 grams per square meter (GSM), spunbond nonwoven 100% polypropylene 30 GSM, 20 GSM and Lycra fibers.

[0132] Therefore, the textile product as defined herein is made of a woven / knitted or non-woven fabric. The amount (percentage) of MgO in the fabric and, when present, the amount (percentage) of APP (by weight) is determined based on considerations known to the person skilled in the art and based on the type of fabric.

[0133] The dispersion as defined herein is suitable for use in any textile product, including but not limited to medical textiles (for example, protective medical masks, medical filters, medical bandages, medical dressings, etc.), clothing articles (for example, masks), fabric filters (for example, for the production of air conditioning filters), clothing, diapers, linens, decorative textiles, industrial textiles, drapery, carpets, tents, sleeping bags, toys, wall fabrics, mattresses or upholstery.

[0134] Every day, many healthcare professionals are exposed to bacteria on their clothes. In addition, the covid-19 coronavirus pandemic has driven the use of disposable protective masks, which can be replaced in whole or in part with washable textile product masks, among other factors.

[0135] Therefore, this aqueous dispersion as defined herein is particularly suitable for use in medical textiles, for example masks.

[0136] As further shown in the appended examples, the aqueous dispersion comprising MgO alone or in combination with APP exerts a significant antibacterial effect within the first 6 hours of the test ( Figure 3A ). Then, a slow increase in the bacterial count is observed ( Figure 3B), although still significantly lower than the degree of increase in bacterial count observed in the control measurement, showing an overall bacteriostatic effect. Importantly, the observed bacteriostatic effect was stable over the remaining period of detection, i.e. up to 48 hours.

[0137] Similar effects were observed when the textile was inoculated with E. coli bacteriophage MS2, wherein a significant antiviral effect was demonstrated for the aqueous dispersion comprising MgO alone or comprising MgO in combination with APP within the first 4 hours of the test ( Figure 2A ). However, in this case, a continuous further decrease in viral count (antiviral effect) could be observed over the entire period of detection up to 24 hours.

[0138] The above results demonstrate the durability of the textile coated with the aqueous dispersion described herein (comprising MgO alone or comprising MgO in combination with APP) which is able to withstand multiple washing cycles and to be used as a bacteriostatic / virucidal and / or antibacterial / antiviral textile product over a time period of 2 to 24 hours before the textile product is cleaned or disinfected.

[0139] The present application will be further described and illustrated by the following examples.

[0140] Example

[0141] Materials

[0142] The materials used for the preparation of the formulations (aqueous dispersions) in the following examples are listed in Table 1 (FR is an abbreviation for flame retardant):

[0143] Table 1 : Materials

[0144]

[0145]

[0146] Method

[0147] Fabric Coating (Application): The fabric is padded with the formulation (interchangeably referred to as "aqueous dispersion"). Paddling is performed using a Rapid HORIZONTAL PADDING MANGLE-Air-Pad, where the formulation is placed between the two rollers of the mangle and the fabric is passed through the two rollers to impregnate both sides of the fabric, thereby allowing the formulation to be absorbed into the fabric, and the fabric is squeezed to the desired moisture content by adjusting the pressure on the rollers. Another method is to knife overcoat the fabric on one side only by rolling the knife over the fabric. The coated fabric is cured at 160 °C for 4 minutes, washed 10 times at 60 °C according to AATCC Standard Practice for Home Laundry or once, 20, 35 or 50 times (as shown below) and dried completely, tested according to AATCC Test Method 100-2019: "Antibacterial finish of textile materials" as detailed below.

[0148] AATCC Test Method 100-2019 : The AATCC 100 method is a standard for antimicrobial fabric performance by the American Textile Industry, consisting of six key steps: preparation of fabric samples (e.g., as described above), sterilization (e.g., using an autoclave at 1.2 atmospheres, 121 °C for 20 minutes), inoculation by applying a microbial suspension (e.g., 1 ml of 1 x 10 5 CFU / ml on the fabric), incubation at 37 °C for the desired incubation period (e.g., from about 20 minutes to about 48 hours), washing / shaking out (e.g., by applying a neutralizing buffer on the fabric sample and collecting the culture with the neutralizing buffer), and counting (colonies formed). The microorganisms are incubated under favorable conditions to clearly show the antimicrobial properties of the test fabric.

[0149] Specifically, the test is performed as follows: samples are prepared by padding the fabric with the above formulation (aqueous dispersion) and cutting the fabric into 4.8 cm discs. The fabric samples are then sterilized using an autoclave and then inoculated with 1 ml of a suspension of the microorganism being tested (e.g., Escherichia coli phage MS2, also known as Escherichia coli virus MS2 (ATCC 15597); Staphylococcus aureus (ATCC 6538); and Escherichia coli (ATCC 8739)) at a bacterial inoculum of 1 x 10 5 CFU / ml and a viral inoculum of 1 x 10 5 PFU / ml. The samples are then incubated at 37 °C for different incubation (contact) times. At the start of the timing and at other different time points (e.g., after 20 minutes, 1.5, 2, 3, 4, 5, or 24 hours), a neutralizing solution (20 ml of Universal Neutralizer by mixing 3 g of lecithin, 30 g of 80、7.84 g Na2S2O3.5H2O, 1 g histidine, 30 g saponin, 1 g tryptone and 8.5 g NaCl were prepared) to wash the fabric samples. Extracted microbial cultures were inoculated according to the method applicable to the relevant microorganism, in particular at 37°C for up to 48 hours.

[0150] Measurement of the Average Secondary Particle Size of Magnesium Oxide Particles : The average secondary particle size of MgO was measured as follows. About 0.15 grams of sample were placed in a 50 ml dry beaker, about 20 ml of isopropanol were added as dispersion medium, the mixture was stirred for about 10-15 seconds using a magnetic stirrer, then dispersed in an ultrasonic homogenizer (Elmasonic P) for three (3) minutes and the particle size distribution was measured with a laser diffraction scattering type particle size distribution measuring instrument (Malvern Mastersizer 2000).

[0151] Citric Acid Activity (CAA 40) : The CAA 40 was measured as the time (seconds) for the reaction of 40% by weight of the product in question with an equivalent volume of citric acid. To this end, 100 ml of 0.4 N citric acid with phenothalin were adjusted to 30°C. Magnesia particles (2 gr of sample) were added to the resulting solution and the solution was stirred using a magnetic stirrer. The time (seconds) from the addition of the magnesia powder to the solution until the color of the solution changed from colorless to pink was measured, which was determined as the CAA value in seconds.

[0152] Measurement of Surface Area : The surface area analysis was measured according to the BET method (based on the method of Brunauer, Emmett and Teller) with a Quantachrome NOVA e2000 instrument using the multipoint BET method.

[0153] Measurement of Apparent Density : The apparent density was measured by gently flowing the sample into a 250 ml recipient until the 250 ml mark was reached. The weight of the contents of the recipient was measured. Apparent density (g / ml) = mass of the sample in the recipient (gr): volume of the recipient (250 ml).

[0154] LOI (Loss on Ignition) : The LOI test was performed as follows. The weighed sample was calcined at 1000°C for 15 minutes. After cooling the sample in a desiccator, the sample was weighed again. The LOI was calculated by the following formula: [(initial sample weight - sample weight after calcination) / initial sample weight] x 100%.

[0155] TGA (Thermogravimetric Analysis)TGA is a method of measuring the mass of a sample as a function of temperature, performed using a TA discovery TGA5500 instrument and a sample of 10 mg of product under test, heated from room temperature to 600°C or 900°C, depending on the expected maximum thermal stability of the compound under test at 10°C / min in air or nitrogen atmosphere.

[0156] Preparation of product 1 : Preparation of different grades of magnesium oxide

[0157] A) Preparation of Magnesium Oxide SIG / HA4 Grade

[0158] In a reactor, a solution of magnesium chloride (MgCl2) at a concentration of 400-550 gr / l is calcined at high temperature (700-850°C). The magnesium chloride thus decomposes into magnesium oxide (MgO) and hydrochloric acid (HC1). The magnesium oxide (MgO) is hydrated into magnesium hydroxide (Mg(OH)2) at a temperature of 60-90°C. The magnesium hydroxide is washed from the soluble salts and milled to the desired particle size, then sent to a high temperature (600 to 950°C) kiln, where the magnesium hydroxide decomposes into magnesium oxide and water. This MgO grade is named “SIG” (the term “SIG” means magnesium oxide derived from magnesium hydroxide, characterized by a very low LOI, indicating almost no hydroxide in the powder). The kiln is composed of several layers, each of which is individually controlled in temperature, and the product (powder) is moved from one layer to another by rabble arms. The rotation speed of the rabble arms determines the residence time in each layer at the specific layer temperature. The results of the analysis of the SIG grade MgO sample are shown in Table 2 below.

[0159] Table 2: Results of the analysis of the MgO SIG grade sample

[0160] Test Units Specification Typical Results Analysis in Magnesium Oxide MgO ％ 96-100.5 99.7 Chlorine in Cl ppm 1000 712 boron as B2O3 ppm 200 max 122 aluminum in terms of AI2O3 ppm 500 max 59 silicon as Si02 ppm 500 max 73 Sodium in Na ppm 200 max 172 Surface Area S.A. m 2 / gr]] 5 min 7.0 sulfate in terms of SO4 ％ 0.4 max 0.09 Calcium in CaO ％ 0.5 max 0.12 Iron in terms of Fe2O3 ppm 700 max 56 Loss on Ignition ％ 3.0 max 0.2 Bulk Density (Un-tapped) g / cc 0.25 min 0.46 Particle Size: 325 Mesh Residue (Wet Sieve) ％ 25 max 5.4 Particle Size: 100 Mesh Residue (Wet Sieve) ％ 5.0 max 0.3

[0161] B) Preparation of Magnesium Oxide HA4 Grade

[0162] The SIG grade obtained according to the above procedure is milled in a dry milling system (jet mill or pin mill), which operates in a range of 2 to 4.5 atmospheres of dry air pressure, with a powder flow rate of 100 to 200 kg / hr. In order to control the particle size distribution, loss on ignition (LOI) and surface area, the mill “jet mill” is kept under a slight negative pressure (very close to zero pressure). This grade is called HA4. The results of the analysis of the HA4 grade MgO sample are shown in Table 3 below.

[0163] Table 3: Results of the analysis of the MgO HA4 grade sample

[0164]

[0165]

[0166] MgO HA4 grade is characterized by d 10 less than 1.5 microns (i.e. 10% of the particles are smaller than this size), d 50 ranging from 1.5 to 6.0 microns (i.e. 50% of the particles are smaller than this size), d 90 ranging from 8.0 to 45 microns (i.e. 90% of the particles are smaller than this size), BET specific surface area greater than 5.0 m 2 / gr, citric acid activity (40) ranging from 25 to 200 seconds, loss on ignition (LOI) ranging from 0.2 to 4.0%, bulk density (not tapped) not less than 0.25 gr / ml.

[0167] The results of the analysis of the MgO HA4 grade sample (subjected to TGA test) are shown in Figure 1A and Figure 1B . Figure 1A The temperature variation up to 600°C was covered and it was proved that the sample weight remained at 99.276%, which indicates a residual amount of magnesium hydroxide of 0.724%. Figure 1B The temperature variation up to 900°C was covered and it was shown that the sample weight was 97.927%, which indicates a residual amount of magnesium hydroxide of 2.073%.

[0168] C) Preparation of Magnesium Oxide SIG-S Grade

[0169] The MgO SIG grade obtained according to the method of Example 1 (A) was treated with steam. The product obtained is called "SIG-S" grade.

[0170] D) Preparation of Magnesium Oxide SIG-SC Grade

[0171] The MgO SIG grade obtained according to the method of Example 1 (A) was treated with steam and carbon dioxide. The product obtained is called "SIG-SC" grade.

[0172] According to the analytical characteristics, the SIG-SC grade sample is characterized by d 10 ranging from 0.8 to 1.5 microns, d 50 ranging from 2.6 to 6.0 microns, d 90 ranging from 10.0 to 45 microns, surface area ranging from 5.0 to 15.0 m 2 / gr, citric acid activity (40) ranging from 100 to 200 seconds, loss on ignition (LOI) ranging from 2.0 to 8.0%, bulk density (tapped 10 times) ranging from 0.25 to 0.35 gr / ml.

[0173] Table 4 shows some properties of the various grades of MgO prepared according to Examples 1 (A-D).

[0174] Table 4: Properties of MgO samples

[0175]

[0176] CAA, citric acid activity; SA, surface area Preparation of Other Magnesium Oxide Grades

[0177] Other grades of magnesium oxide were prepared by varying the properties of the kiln (e.g., time, temperature, etc.) to vary the particle size distribution, surface area, and reactivity of the magnesia particles. Other examples of MgO grades tested were E-10A and RA-40 (periclase mineral) which are characterized as having 2-12% magnesium hydroxide and / or magnesium carbonate. The characteristics of the E-10A and RA-40 MgO grades are shown in Table 5 below.

[0178] The physical properties of the SIG grade MgO prepared as described above, as well as commercially available E-10A and RA-40 MgO, are shown in Table 5 below. A sample of magnesium hydroxide was provided as a reference.

[0179] Table 5: Particle size distribution and surface area of MgO and Mg(OH)2compounds

[0180]

[0181] Preparation 2: Aqueous dispersion of magnesium oxide

[0182] An aqueous dispersion of magnesium oxide was prepared according to the following procedure using any of the magnesium oxide grades prepared as described above (or commercially available). First, water was added. Then a liquid dispersant (e.g., TERSPERSE 2735) was added to the water and stirred. While stirring, the MgO powder of the desired grade was gradually added and stirring was continued for 30 minutes (dissolver IKA, 300-600 rpm). Then, an acrylic binder was added, and finally, a thickener (e.g., HEC QP-100MH) was added as needed to modify the viscosity.

[0183] The compositions of two exemplary HA4 grade MgO aqueous suspensions prepared according to the above procedure (one for use in knitted / woven fabrics and the other for use in nonwoven fabrics) are shown in Tables 6 and 7, respectively.

[0184] Table 6: MgO dispersion for coating knitted / woven fabrics

[0185]

[0186] Table 7: MgO dispersion for coating lightweight nonwoven fabrics

[0187]

[0188] When a softener was added, the final concentration was 2% by weight.

[0189] Water dispersions containing different grades of MgO (e.g. SIG grade, E-10A and RA-40) were prepared according to the procedure above, e.g. with the specific amounts of ingredients shown in Table 6 above or as shown in the examples below.

[0190] The water content in the dispersion varies depending on the water absorption capacity of the fabric type and the final percentage addition required for the fabric (approximately 2% to 20%). It is noted that dilute formulations are suitable for coating water-absorbent fabrics, while concentrated formulations are suitable for coating non-water-absorbent fabrics.

[0191] Preparation 3: Water dispersion of ammonium polyphosphate (APP)

[0192] Ammonium polyphosphate (also referred to herein as ammonium superphosphate or AG, 300 g) was added to a vessel previously filled with water (484.5 g), dispersant (TERSPERSE 2735, 12 g) and wetting agent (AGRI-MEAL® WP, 1.2 g) stirred at a rate of 300 to 600 RPM (using an IKA dissolver). The dispersion was continuously stirred for 15 minutes, then an acrylic binder (AC-178, 150 g) was added. Finally, a thickening agent (hydroxyethyl cellulose, Cellosize HEC QP-100MH, 0.57 g) was added. Stirring was continued for a further 30 minutes. The concentration of ammonium polyphosphate in the dispersion was 31.6 wt.%. The composition is shown in Table 8 below. Table 8: Water dispersion of ammonium polyphosphate containing 40% solids

[0193] Table 8: Water dispersion of ammonium polyphosphate containing 40% solids

[0194]

[0195] Preparation 4: Water dispersion of MgO / APP

[0196] A formulation containing MgO powder and AG was prepared as follows. First, water was added. Then a liquid dispersant (TERSPE RSE 2735, 5.28 g) was added to the water and stirred at a rate of 300 rpm (using an IKA dissolver). The MgO powder (48 g) was gradually added while stirring was continued for 30 minutes. Then, the AG dispersion (40 g of a 40% solids containing dispersion, prepared as described in Table 8 above) was added. Next, an acrylic binder (AC-178, 54.4 g) was added. Finally, a thickening agent (HEC QP-100MH, 1 g) was added. The amounts of the individual components are shown in Table 9 below: Table 9: MgO HA4 grade and

[0197] Table 9: MgO HA4 grade and ​​Suspension of AG

[0198]

[0199] The amount of binder varies depending on the application desired. For example, when wash durability is required, the amount of binder used is higher; in contrast, when fabric flexibility is required, the amount of binder used is lower.

[0200] Preparation 5: Aqueous dispersion of Mg(OH)2(S-10 grade)

[0201] For reference, a dispersion of Mg(OH)2(S-10 grade) in water was also prepared by adding an acrylic binder, a surfactant, and a polymeric thickener to the Mg(OH)2slurry, as detailed below.

[0202] First, solid Mg(OH)2(60 g, ICL-IP FR-S-10) was dispersed in deionized water (219 g) with dispersant (Tersperse 2735, Huntsman) (6.6 g), 50% acrylic binder (AC-178, B.G. polymer) (15 g), and hydroxyethyl cellulose (HEC) QP-100MH (Dow) (1 gr). This dispersion was used on 50% polyester / cotton fabric.

[0203] Alternatively, solid Mg(OH)2(60 g) was dispersed in deionized water (478 g) with surfactant (such as TERSPERSE 2735 (6.6 g)), 50% acrylic binder (such as AC-170, B.G. Polymer) (34 g), and thickener (such as HEC, 2 g). This dispersion was padded onto 100% cotton textiles.

[0204] The composition of the two dispersions prepared as described above (for coating 50% and 100% cotton fabric) is shown in Table 10.

[0205] Table 10: Mg(OH)2fabric dispersions

[0206]

[0207] Example 1: Fabric coated with MgO HA4 alone or with MgO HA4 in combination with Antibacterial properties of fabrics coated with AG

[0208] The purpose of the study reported in this example was to evaluate the antibacterial effect of applying to a fabric a dispersion containing MgO HA4 grade alone, while evaluating the antibacterial effect of a dispersion containing MgO HA4 grade in combination with APP (AG).

[0209] ​To this end, each of the following dispersions (prepared as described above) was used to fill a woven 12% Nylon 66, 88% cotton 170GSM fabric sample, respectively, in the manner described above: a dispersion containing HA4 grade MgO (Preparation 1), a dispersion containing AG (Preparation 2), or a dispersion containing both agents (Preparation 3).

[0210] The samples were labeled 1A, 2A, and 3A, respectively, see Table 11 below, to refer to the first experiment performed. Additional experiments were labeled with “B”, “C”, etc.

[0211] The fabrics were then tested in accordance with the AATCC Test Method 100-2019, described above. Briefly, the fabrics were cut into 4.8 cm discs and autoclaved. The fabric discs were then inoculated with 1 ml of a bacterial suspension (S. aureus and E. coli). At the start of the time period and after 24 hours, the discs were washed with a neutralizing solution (20 ml of the universal neutralizer described above) and the extracted bacteria were inoculated by pour plate method using agar nutrient media. The inoculated petri dishes were incubated at 37°C for 48 hours.

[0212] Tables 11 and 12 below show the results of two experiments performed as described above, respectively, on two different fabric types: woven 12% Nylon 66, 88% cotton 170GSM (grams per square meter); and pocketing woven 12% Nylon 66, 88% cotton 170GSM.

[0213] Table 11: Antimicrobial Effectiveness against S. aureus and E. coli

[0214]

[0215] *“% Add” refers to the weight percent of solids (MgO, APP, or combinations thereof, and all additives, such as binders) included in the dispersion in the total fabric weight.

[0216] **“% MgO” refers to the weight percent of MgO in the total fabric weight.

[0217] As can be seen from Table 11, the bacterial count on the untreated fabric (control) increased by four (4) orders of magnitude.

[0218] The magnesite had an antimicrobial effect on the HA4 grade MgO treated fabric sample 1A, with no change in bacterial count after 24 hours compared to the start of the time period. The AG treated fabric sample 2A showed a similar antimicrobial effect.

[0219] However, the fabric samples treated with HA4 grade MgO and ​The fabric sample 3A treated with the combination of AG showed strong antibacterial effect as the bacterial count was reduced by about three (3) orders of magnitude after 24 hours compared to the starting point of the time.

[0220] Table 12 below shows the other test results obtained by coating 12% nylon 66, 88% cotton 170 GSM woven for pocket bags with HA4 grade MgO alone (sample labeled IB) or this substance in combination with AG (sample labeled 3B) and inoculating the fabric with bacteria.

[0221] Table 12: Antibacterial effect against S. aureus and E. coli

[0222]

[0223] *“% addition” refers to the weight percentage of solids (MgO, APP or their combination and all additives such as binders) included in the dispersion in the total fabric weight.

[0224] **“% MgO” refers to the weight percentage of MgO in the total fabric weight.

[0225] As shown in Table 12, on the untreated fabric samples (two control samples), the bacterial count increased by about four (4) orders of magnitude.

[0226] On the fabric sample labeled IB, after treatment with HA4 grade MgO (7.6%), magnesite had a strong bacteriostatic effect and a smaller antibacterial effect, as the bacterial count was reduced by about one order of magnitude after 24 hours compared to the starting point of the time.

[0227] However, on the fabric sample labeled 3B treated with HA4 grade MgO (5.9%) and AG (1.5%), a strong antibacterial effect was shown, as the bacterial count was reduced by about three (3) orders of magnitude after 24 hours compared to the starting point of the time.

[0228] The above results show that the coating of the fabric with the dispersion containing HA4 grade MgO and AG in combination has an antibacterial effect.

[0229] Example 2: Antiviral properties of fabrics coated with HA4 grade MgO alone or this substance in combination with AG

[0230] The purpose of the study reported in this example was to evaluate the antiviral effect of applying to the fabric a dispersion containing MgO HA4 grade, alone or in combination with AG.

[0231] To this end, a spunbond nonwoven 100% polypropylene 30GSM fabric was coated with a dispersion containing solely HA4 grade MgO (Preparation 1) or a dispersion containing a combination of HA4 grade MgO and AG (Preparation 3). The fabric was then tested according to AATCC Test Method 100-2019.

[0232] Briefly, the fabric was cut into 4.8 cm discs and autoclaved. The fabric discs were inoculated with 1 ml of suspended E. coli bacteriophage MS2 (ATCC 15597). At the start of the timing and after 1.5, 2, 3, 4 and 24 hours, the discs were washed with neutralization solution (20 ml of the general neutralizer detailed above) and the extracted E. coli bacteriophage was inoculated according to the double layer method (Standard Methods for the Examination of Water and Wastewater. 22ndedition. American Public Health Association, American Water Works Association, Water Environment Federation, section: SM 9224C).

[0233] The following Table 13 shows the results obtained from the above experiment. The samples treated with MgO and with MgO / APP dispersion are labelled 1C and 3C, respectively.

[0234] Table 13: Antiviral effect against E. coli bacteriophage MS2

[0235]

[0236] * The viral count was similar to the viral count obtained at the start of the timing for the control.

[0237] “% MgO” relates to the weight percentage of MgO in the total fabric weight. Abbreviations: Treat., treatment; Cont., control; hr, hour.

[0238] As shown in Table 13 above, the viral count on the fabric sample not treated (control) remained at approximately the same level throughout the experiment, as expected.

[0239] A strong antiviral effect was observed on the fabric sample treated with MgO (8.66%) labelled 1C, showing a reduction of about three (3) orders of magnitude in the viral count after 24 hours compared to the start of the timing. As can be seen from Table 13, the reduction in viral count was gradual over the time of measurement, with a clear antiviral effect even after 24 hours of incubation.

[0240] Fabric samples labeled 3C treated with a combination of HA4 grade MgO (7%) and AG (0.7%) showed similar antiviral efficacy.

[0241] The above results show that fabric coating with dispersions comprising HA4 grade MgO or comprising HA4 grade MgO in combination with AG also provided antiviral efficacy.

[0242] The antiviral activity shown in Table 13 above is also shown in graphical form, in Figure 2A shows results obtained over the first 4 hours of the experiment and in Figure 2B shows results obtained over the 24 hours of the experiment.

[0243] As Figure 2A shown, fabric coating with dispersions comprising MgO alone was slightly more efficient than fabric coating with dispersions comprising both agents over the first 4 hours of the experiment. However, over time (i.e. 24 hours experiment, Figure 2B ), dispersions comprising MgO alone and dispersions comprising MgO and AG showed similar antiviral activity.

[0244] Example 3: Duration of antibacterial efficacy of fabrics coated with HA4 grade MgO alone or with HA4 grade MgO in combination with AG

[0245] Then, the antibacterial efficacy of fabrics coated with HA4 grade MgO in the absence and presence of AG was investigated over an extended duration of up to 48 hours.

[0246] To this end, spunbond nonwoven 100% polypropylene 30 GSM was padded with dispersions as detailed above. Briefly, fabrics were coated with dispersions comprising HA4 grade MgO alone (Preparation 1), with dispersions comprising HA4 grade MgO alone in the presence of a softener (Preparation 1S), or with dispersions comprising HA4 grade MgO and AG (Preparation 3) as shown in Table 14 below.

[0247] At higher addition levels, a softener is required in the dispersion. The following analysis tests whether the addition of a softener to the dispersion has any impact on the antibacterial activity of the dispersion, among other factors.

[0248] ​The fabrics were tested based on the above standard AATCC test method 100-2019. In brief, the coated fabrics were cut into 4.8 cm discs, sterilized in an autoclave and then inoculated with 1 ml of a bacterial suspension (Staphylococcus aureus, ATCC 6538). At the start of the timing and after 15 minutes, 60 minutes, 2, 6, 24 and 48 hours, the discs were washed with a neutralizing solution (20 ml) and the extracted bacteria were inoculated on nutrient agar at 37°C for 48 hours. The results are shown in Table 14 below.

[0249] Table 14: Persistence of the antibacterial effect against Staphylococcus aureus over time

[0250]

[0251] “% MgO” relates to the weight percentage of MgO in the total fabric weight. Abbreviations: Treat., treatment; soften., softener; TexFR, AG; Sam. No., sample number; Cont., control.

[0252] As shown in Table 14, over the 48 hours of the experiment, the bacterial count increased uninterruptedly by about four (4) orders of magnitude on the fabric samples that were not treated (control).

[0253] The fabrics were coated with a dispersion comprising HA4 grade MgO (sample 1D), a dispersion comprising HA4 grade MgO and softener (sample 1SD) or a dispersion comprising HA4 grade MgO and AG (sample 3D) and the results were a strong bacteriostatic effect observed over the entire time range of the test, i.e. up to 48 hours.

[0254] It is worth noting that after six hours, a moderate antibacterial effect was observed on all the tested fabrics (i.e. samples 1D, 1SD and 3D) with a reduction of one to two orders of magnitude in the bacterial count compared to the start of the timing. The reduction in the bacterial count after six hours for the above samples is also shown in graph form in Figure 3A where only the control sample and samples 1D and 3D are shown.

[0255] As mentioned above, the softener is required at higher addition levels. The above results show that the addition of the softener does not impair the antibacterial activity of the dispersion.

[0256] In addition, as shown in Table 14 and in graph form in Figure 3B , it is shown that the bacterial count of the tested coated fabrics increased slightly after six hours. However, after 48 hours, a significant reduction in the bacterial count (by 4-5 orders of magnitude) was observed compared to the control sample, indicating that the bacteriostatic effect is stable over the entire time range of the test.

[0257] The above examples show that the fabrics as described above exhibit strong antimicrobial properties for up to 6 hours, and thus can be used at least 6 hours before washing or disinfecting.

[0258] Example 4: Influence of multiple washing cycles on the antimicrobial activity of MgO dispersions on fabrics

[0259] The influence of multiple washing cycles on fabrics coated with HA4 grade MgO dispersions was further investigated. To this end, three different HA4 grade MgO water dispersions were prepared according to the above described method, each comprising a different binder, i.e. AC-178, AC-2403 or AC-75032. The composition of the prepared water dispersions is detailed in Table 6 above.

[0260] The above described dispersions were filled on (respectively) polyamide-Lycra fiber samples as described above. After coating with the various MgO dispersions, the fabric samples were cured at 160°C for 4 minutes and washed 10, 20, 35 or 50 times and dried, and tested according to the AATCC test method 100-2019 as described above.

[0261] In short, the fabrics were cut into 4.8 cm discs, sterilized with an autoclave and inoculated with 1 ml of a bacterial suspension (Staphylococcus aureus, ATCC 6538). At the start of the time count and after 2, 5 and 24 hours, the discs were washed with a neutralizing solution (20 ml) and the extracted bacteria were inoculated on nutrient agar at 37°C for 48 hours. Table 15 below shows the results of the above described experiments.

[0262] Table 15: Antimicrobial effect of HA4 grade MgO coated fabrics against Staphylococcus aureus after multiple washing cycles

[0263]

[0264]

[0265] The bacterial count at the start of the time count was similar to the bacterial count obtained as control measurement at the start of the time count. “% MgO” relates to the weight percentage of MgO in the total fabric weight. Abbreviations: Treat., treatment; Sam. No., sample number; Cont., control; cycles, washing cycles.

[0266] As shown in Table 15 above, similar observations as in the previous examples were made, i.e. an increase in bacterial count was observed (in particular, an increase of 4 orders of magnitude) in the absence of a MgO coating.

[0267] Notably, in the presence of MgO dispersions comprising various binder types, i.e. AC-178, AC-2403 and AC-75032, respectively Figure 4A ,Figure 4B and Figure 4C As shown in Figures 2, 3, 4 and 5, after five (5) hours of incubation, a decrease of one to two orders of magnitude in bacterial count was observed. This is evidence of the antibacterial effect. From this point in time until the end of the experiment, the bacterial count gradually increased, but in any case, a bacterial count at least two orders of magnitude lower than that measured for the control was observed.

[0268] The analysis of the bacterial counts of the various dispersions obtained under different washing conditions for 10, 20, 35 and 50 cycles showed that the number of washing cycles applied to the coated fabric had a slight influence. For example, when using the AC-178 or AC-2403 adhesives, 10 or 20 washing cycles had an advantage, respectively, as shown in Figures 6 and 7; while when using the AC-75032 adhesive, 20 washing cycles had an advantage, as shown in Figure 8. Figure 4A and Figure 4B Figure 4C

[0269] Notably, when analyzing the bacterial counts obtained after a 24-hour incubation period, the dispersion containing the AC-75032 adhesive had an advantage over the other adhesives used, as the fabric samples behaved similarly, regardless of the number of washing cycles applied to the fabric, as shown in Figure 9. Figure 4C

[0270] Furthermore, at all time points, a clear bacteriostatic effect and a slight antibacterial effect was shown, even after the fabric samples had undergone 50 washing cycles and in the case of the use of all types of dispersion, relative to the control measurements. These effects were particularly evident after a five-hour incubation period.

[0271] Without wishing to be bound by theory, the slight variation in the percentage of MgO added to the total weight of the fabric did not affect the antibacterial or bacteriostatic activity of the MgO dispersion.

[0272] Example 5 (Reference Example): Antibacterial activity of Mg(OH)2-impregnated textiles

[0273] As a reference, the use of aqueous dispersions containing different concentrations of Mg(OH)2as antimicrobial finishing agents for textiles was further tested. Two types of textiles were used: 50% / 50% polyester fiber / cotton 175 g / m 2 and 100% cotton 200 g / m 2 .

[0274] ​​​The fabric was first coated with a Mg(OH)2 dispersion, prepared and diluted (with water) as described above to obtain the final (add-on) percentage desired for Mg(OH)2, and then cured at 160 °C for 4 minutes. Several fabrics were obtained due to the different dispersions used to fill the fabric, which had different total solids and Mg(OH)2 percentages. Table 16 below gives the percentage of total solids (also referred to herein as “add-on” percentage) and the percentage of Mg(OH)2 deposited on the fabric sample for the 50 / 50 fabric and the 100% cotton fabric.

[0275] Table 16: Percentage of total solids and Mg(OH)2 in the coated fabric

[0276]

[0277] Then, the two fabric types were tested according to AATCC Test Method 100-2019 by inoculating the fabric with Staphylococcus aureus (ATCC 6538) as described above.

[0278] For both fabric types, the percentage of bacteria reduction increased as the amount of Mg(OH)2 in the fabric increased. As shown in Table 17 below, for the 50% / 50% polyester / cotton fabric, the percentage of bacteria reduction increased from 0 at 2.36% Mg(OH)2 content to 83.4% reduction at 8.9% Mg(OH)2 content. On the control fabric, a 0.5 order of magnitude increase in bacterial growth was observed (data not shown).

[0279] Table 17: Reduction (%) in bacterial count of Staphylococcus aureus on 50 / 50 woven cotton polyester coated with Mg(OH)2 dispersion after 24 hours of incubation time

[0280] [Mg(OH)2(% in textile)] Bacterial Reduction (%) 2.36 0.0 4.8-5.1 60.7 5.65-6.75 72.4 7.2 77.6 8.9 83.4

[0281] On the same fabric type, filling with further dispersions containing Mg(OH)2 reduced the bacterial count, as shown in Table 18:

[0282] Table 18: Reduction (%) in bacterial count of Staphylococcus aureus on 50 / 50 woven cotton polyester coated with Mg(OH)2 dispersion after 24 hours of incubation time

[0283] [Mg(OH)2(% in textile)] Bacterial Reduction (%) 6.53-7.59 60.69 7.60-8.7 81.92

[0284] In addition, the antimicrobial activity of the 100% cotton knit fabric filled with a dispersion containing Mg(OH)2 after 5 laundry machine cycles was as shown in Table 19:

[0285] Table 19: Reduction in bacterial count of S. aureus on 100% cotton knitted fabric containing Mg(OH)2after 24 hours of incubation time and after 5 laundry cycles

[0286]

[0287] In further experiments on 100% cotton fabric filled with dispersions containing Mg(OH)2after several laundry cycles, the results are shown in Table 20 below, with the percentage of bacterial reduction increasing from 75.4% at 4.3% Mg(OH)2content in the textile to 98.9% reduction at 12.8% Mg(OH)2content in the textile. In comparison, the control fabric samples showed an increase in bacterial numbers of two orders of magnitude.

[0288] Table 20: Reduction in bacterial count of S. aureus on 100% cotton knitted fabric containing Mg(OH)2after 24 hours of incubation time

[0289] [Mg(OH)2(% in textile)] Bacterial Reduction (%) 4.3 75.4 5.2-6 91.6 6.6-7.1 97.0 12.80 98.9

[0290] Example 6: Antimicrobial activity of 100% cotton knitted fabric coated with different magnesium oxide compounds

[0291] The antimicrobial activity of water dispersions containing different grades of magnesium oxide coated on 100% cotton knitted fabric was then tested against S. aureus (ATCC 6538). As a reference, the antimicrobial activity of fabric coated with a water dispersion containing Mg(OH)2was also determined.

[0292] First, different water dispersions of Mg(OH)2or MgO (60 g each) were prepared as generally described above, with MgO being SIG, E-10A and RA-40 grades, and Mg(OH)2being S-10, HD-5 and HD-12 grades (Table 6).

[0293] These dispersions were filled on 100% cotton knitted fabric, and the fabric was cured at 160°C for 4 minutes. The percentage of Mg(OH)2 / MgO deposited on the fabric samples was comprised between 5% and 10%, as detailed in Table 21 below. The antimicrobial activity of the test fabrics was tested without washing the coated and cured fabric or after 5 laundry cycles. The results are shown in Table 21 below.

[0294] Table 21: Reduction in bacterial count of S. aureus on 100% cotton knitted fabric containing Mg(OH)2or MgO after 24 hours of incubation time and reduction in log

[0295]

[0296] After reviewing Table 21, it was first observed that all MgO grades had better antibacterial efficacy than the Mg(OH)2grades. Among the three tested MgO grades, the water dispersion containing MgO SIG grade had the highest efficacy against the tested bacteria.

[0297] Furthermore, in most cases, washing the fabric after the coating step did not have any significant effect on the properties of the fabric.

[0298] To evaluate the effect of the stability of the magnesia dispersion on the bacterial activity, the magnesia dispersion was aged for one week and immediately after, it was filled on the fabric (i.e. magnesium oxide dispersion). No significant difference in the fabric antimicrobial activity of the two treated fabrics was observed (data not shown).

[0299] Example 7: Antimicrobial activity of commercial products

[0300] As another reference, the test was repeated on commercial antimicrobial socks and kitchen wipes (Table 22). Briefly, the antimicrobial socks and kitchen wipes detailed in Table 22 below were inoculated with S. aureus using the method detailed above for the magnesium oxide coated fabrics. As shown by the results presented in Table 22 below, only the active ingredient triclosan (product name “Ultra-Fresh NM-V2” kitchen wipes) had similar antimicrobial activity to MgO.

[0301] Table 22: Percentage reduction and log reduction of bacterial counts of S. aureus on silver socks, kitchen wipes and triclosan wipes after 24 hours of incubation time

[0302]

[0303] As an additional reference, the test was repeated on commercial fabrics containing zinc oxide or copper, which are used among other uses to prepare face masks. These fabrics were compared to a spunbond nonwoven polypropylene 30GSM filled with a dispersion containing MgO prepared as described above.

[0304] The results of the ATCC test performed in the presence of E. coli phage MS2 are presented in Table 23 below. As is evident from Table 23 below, the spunbond nonwoven polypropylene 30GSM fabric filled with a dispersion containing MgO was the most effective in reducing viral counts after 24 hours of incubation time compared to the control or the commercial product zinc oxide-based face mask or copper-based (nonwoven) face mask.

[0305] Table 23: ATCC test with E. coli phage MS2 on commercial products and spunbond nonwoven polypropylene 30GSM

[0306]

[0307] Example 8: Antimicrobial activity of dispersions comprising different grades of magnesite coated on 65% polyester 35% cotton fabric

[0308] In addition to the experimental results described above, textile formulations of various grades of MgO (i.e. HA4, SIG-S and SIG-SC MgO grades, prepared as described above) were further prepared, in particular when preparing the dispersions listed in Table 6 above, using 27.2 and 1.44 gr of AC-2403 (binder) and HEC (thickener), respectively. The dispersions were left to mix for 2 hours.

[0309] Then, the dispersions comprising HA4, SIG-S or SIG-SC detailed above or the dispersions comprising HA4, SIG-S or SIG-SC diluted two times with water were filled in 65% polyester 35% cotton 200 gr / m2 2 fabrics.

[0310] As described above, the antimicrobial activity of the fabrics was tested using the ATCC 100-2004 method. Briefly, the fabrics were cut into samples of 4.8 cm in diameter and sterilized by autoclave. Then, two (2) samples of each test fabric were inoculated with S. aureus bacteria (2 ml, ATCC 6538). The samples were tested at the beginning of the time (0) and after 24 hours of incubation. At this time, a neutralizer (20 ml) was added, the samples were inoculated on agar plates and incubated at 37°C for 48 hours. The results are summarized in Table 24 below.

[0311] Table 24: Antimicrobial activity of dispersions comprising different grades of MgO coated on 65% polyester 35% cotton fabric after 24 hours of incubation time

[0312]

[0313] *“% addition” refers to the weight percentage of solids (MgO, APP or their combination and all additives, such as binder) included in the dispersion in the total fabric weight.

[0314] **“% MgO” refers to the weight percentage of MgO in the total fabric weight.

[0315] As shown in Table 24, on the fabric not treated with MgO, the bacterial count increased by three (3) orders of magnitude.

[0316] The fabric samples treated with HA4 grade MgO (to obtain a percentage of 7.35% and 3.71% in the fabric) and the fabric sample treated with SIG-S grade MgO (to obtain a percentage of 5.05% in the fabric) showed that the magnesite has a strong bacteriostatic effect, with no change in the bacterial count after 24 hours compared to the beginning of the time.

[0317] Fabric samples treated with SIG-S and SIG-SC grade MgO respectively (final percentages of 9.36% and 8.76% respectively) showed strong biostatic effect and a slight antibacterial effect, showing a reduction in bacterial count of one order of magnitude after 24 hours compared to the starting point of the count.

[0318] Notably, the fabric sample treated with SIG-SC grade MgO (final percentage of 4.31%) showed a strong antibacterial effect, showing a reduction in bacterial count of four (4) orders of magnitude after 24 hours compared to the starting point of the count.

[0319] Example 9: Antibacterial activity of dispersions containing HA4 grade MgO applied to a single surface of a non-woven 100% polypropylene fabric

[0320] Next, the antibacterial effect of dispersions containing HA4 grade MgO was tested, the dispersions containing HA4 grade MgO being used to obtain a total percentage of addition of 10.0% and 10.4%. The dispersions were prepared as detailed above (Table 6).

[0321] In this example, the dispersions were applied only to one of the surfaces of the fabric (by back-coating, the surface is referred to as surface "A" or "B", i.e. only on surface A or only on surface B) and the antibacterial effect of the treated fabric was compared. Table 25 below shows the results of these experiments.

[0322] Table 25: Staphylococcus aureus (ATCC 6538) bacterial count on 100% polypropylene fabric coated with MgO HA4 grade dispersions

[0323]

[0324] As shown in Table 25, on the fabric sample not treated with magnesite (control), an increase in bacterial count of two orders of magnitude was observed.

[0325] The fabric samples treated with HA4 grade MgO (percentage of addition of 10.0% or 10.4%) showed that the magnesite has a strong biostatic effect, showing no change in the number of bacteria after 24 hours compared to the starting point of the count.

[0326] Furthermore, it can be seen that for the two dispersions tested, the biostatic effect obtained when the dispersion is filled on surface A is similar to the biostatic effect obtained when the dispersion is filled on surface B, meaning that the magnesite penetrates the fabric and reaches both sides.

[0327] Similar results were obtained for 100% polypropylene fabric samples inoculated with E. coli, which were coated on one of the surfaces with a dispersion of MgO HA4 grade as prepared above (i.e. with a total percentage of addition of 10.0% or 10.4%). Table 26 below shows the results of these experiments.

[0328] Table 26: Bacterial count of E. coli on 100% polypropylene fabric coated with a dispersion of MgO HA4 grade

[0329]

[0330] As can be seen from Table 26, on the fabric not treated with magnesite (control), an increase of four orders of magnitude of the bacterial count was observed.

[0331] On the contrary, all the fabric samples treated with MgO of HA4 grade showed that magnesite has an antibacterial effect, showing a relatively small variation of the bacterial count after 24 hours compared to the starting point of the time.

[0332] In addition, it can be seen that the antibacterial effect is shown on both sides of the fabric, regardless of the side on which the magnesite was applied, meaning that the magnesite penetrates the fabric and reaches both sides.

[0333] Example 10: Effect of varying the percentage of MgO in the fabric on the antibacterial activity of the fabric coated with a dispersion of MgO of HA4 grade

[0334] Finally, the antibacterial effect of a water dispersion containing MgO of HA4 grade coated on a non-woven 100% polyester fabric against S. aureus was tested, varying the percentage of MgO in the fabric. For this purpose, the dispersion prepared as described in Table 7 above was prepared and diluted.

[0335] Table 27: Bacterial count of S. aureus (ATCC 6538) on 100% polyester fabric

[0336]

[0337] *“% addition” refers to the percentage by weight of solids included in the dispersion in the total weight of the fabric.

[0338] **“% Mg” and “% MgO” refer to the percentage by weight of Mg and MgO, respectively, in the total weight of the fabric.

[0339] As can be seen from Table 27, on the fabric not treated with magnesite (i.e. the control sample), an increase of three (3) orders of magnitude of the bacterial count was observed.

[0340] In contrast, the fabric samples treated with HA4 grade MgO achieved overall addition percentages of 7.34%, 7.30%, and 6.80%, indicating that magnesia has an antibacterial effect and showed relatively small changes in bacterial counts after 24 hours compared to the starting point of the timer.

[0341] Importantly, it is noteworthy that, as shown in the last row of Table 27, the dispersion applied to the fabric sample contained all the formulation components (i.e., binder, surfactant, thickener, and water), except for the addition of magnesia. An increase of three (3) orders of magnitude in bacterial count was observed in this fabric sample, indicating that the magnesia particles were crucial for antibacterial or bactericidal activity.

[0342] While the invention has been described using specific embodiments, many modifications and variations are possible. Therefore, it should be understood that the invention is not intended to be limited in any way beyond the scope of the appended claims.

Claims

1. An antimicrobial textile finishing aqueous dispersion, the aqueous dispersion comprising: 37 to 94 wt% water; 2 to 20 wt% magnesium oxide; 0.5 to 4 wt% polymeric anionic surfactant; and 0.1 to 0.5 wt% hydroxyethyl cellulose thickener.

2. The aqueous textile finishing liquor according to claim 1, wherein, The aqueous dispersion is free of a binder.

3. The aqueous textile-finishing liquor according to claim 1 or 2, wherein, The magnesium oxide is characterized by having: d 10 The range is from 0.5 μm to 1.5 μm, d 50 The range is from 1.5 μm to 6.0 μm and d 90 The particle size distribution ranges from 5.0 μm to 45.0 μm, and the range is from 5.0 to 25.0 μm. 2 / gr surface area, loss on ignition ranging from 0.2% to 8.0%, bulk density ranging from 0.25 to 0.50gr / ml, and citric acid activity CAA 40 ranging from 25 to 200 seconds, which is the time for 40% of the weighed product to react with an equivalent volume of citric acid.

4. The aqueous textile-finishing liquor according to claim 1 or 2, wherein, said magnesium oxide is characterized by having: d 10 a particle size distribution ranging from 0.5 pm to 1.5 pm, d 50 a particle size distribution ranging from 1.5 pm to 6.0 pm and d 90 a particle size distribution ranging from 5.0 pm to 45 pm, a surface area ranging from 5.0 to 25.0 m 2 / gr, a loss on ignition ranging from 0.2% to 5.0%, a bulk density ranging from 0.30 to 0.50 gr / ml, a citric acid activity CAA 40 ranging from 80 to 200 seconds, CAA 40 being measured as the time for 40% of the weighed product to react with an equivalent volume of citric acid.

5. The aqueous textile-finishing liquor according to claim 1 or 2, wherein, said magnesium oxide is characterized by having: d 10 a particle size distribution ranging from 0.8 pm to 1.5 pm, d 50 a particle size distribution ranging from 2.5 pm to 6.0 pm and d 90 a particle size distribution ranging from 10.0 pm to 45 pm, a surface area ranging from 5.0 to 15.0 m 2 / gr, a loss on ignition ranging from 2.0% to 8.0%, a bulk density ranging from 0.25 to 0.35 gr / ml, a citric acid activity CAA 40 ranging from 100 to 200 seconds, CAA 40 being measured as the time for 40% of the weighed product to react with an equivalent volume of citric acid.

6. The aqueous textile-finishing liquor according to claim 1 or 2, wherein, said magnesium oxide is characterized by having a particle size distribution ranging from 1.0 pm to 1.5 pm, a d 10 50 a particle size distribution ranging from 2.5 pm to 6.0 pm and a d 90 a particle size distribution ranging from 10.0 pm to 45.0 pm, a surface area ranging from 5.0 to 10.0 m 2 / gr, a loss on ignition ranging from 0.2% to 6.0%, a bulk density ranging from 0.3 to 0.5 gr / ml, a citric acid activity CAA 40 ranging from 100 to 200 seconds, CAA 40 being measured as the time of reaction of 40% of the weighed product with an equivalent volume of citric acid.​ 7. The textile finishing aqueous dispersion of claim 1 or 2, further comprising ammonium phosphate or ammonium polyphosphate.

8. The aqueous textile finishing liquor according to claim 7, wherein, The ammonium polyphosphate is aluminum ammonium polyphosphate.

9. The textile finishing aqueous dispersion of claim 8, the aqueous dispersion comprising: 67 to 90 wt% water; 5 to 20 wt% magnesium oxide; 0.5 to 4 wt% aluminum ammonium polyphosphate; 0.5 to 4 wt% polymeric anionic surfactant; and 0.1 to 0.5 wt% hydroxyethyl cellulose thickener.

10. A textile product coated with an antiviral or antimicrobial finish, the antiviral or antimicrobial finish comprising magnesium oxide, polymeric anionic surfactant, hydroxyethyl cellulose thickener, and an acrylic acid salt / binder, wherein the amount of magnesium oxide is at least 2 wt% of the textile product.

11. The textile product of claim 10, the antiviral or antibacterial finish further comprising ammonium phosphate or ammonium polyphosphate, wherein, The amount of magnesium oxide is at least 2% and the amount of ammonium phosphate or ammonium polyphosphate is at least 0.5% relative to the weight of the textile product.

12. The textile of claim 10 or 11, wherein, The antiviral or antimicrobial finish is added in an amount of 2 to 20 wt% of the total dry weight of the fabric.

13. The textile product of any of claims 10-12, wherein, The textile product is a medical textile product, a face mask, or a fabric filter.

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