THE USE OF QUATERNARY AMMONIUM BETATNES IN THE PREVENTION OF MOLD, MILDEW, AND FUNGUS IN NEW AND/OR EXISTING CONSTRUCTION

FIELD OF THE INVENTION

[0001] The present invention relates to the use of quaternary ammonium compositions in the prevention of unwanted microbial growth such as mold, fungus, and mildew in new and/or existing construction. BACKGROUND OF THE INVENTION

[0002] It has been presented and discussed on numerous occasions that certain molds, mildews, and/or funguses pose a health hazard to many individuals, and the issue of remediation of such organisms is a constant problem in the construction industry. For example, certain buildings and locations within buildings lend themselves to more readily promote or facilitate the growth of funguses, molds, and/or mildews, e.g. basements, crawl spaces, etc. Further, depending upon the particular type of building, and the particular geographic area in which the building is found, these buildings may provide suitable environments for microbial growth. For instance, spaces that are not adequately ventilated and/or exposed to moisture can contribute to growth of microbes, and in some instances in new construction, some spaces are often not ventilated until final steps in the construction, allowing mold to grow and colonize at unacceptable levels, and the mold may quickly spread to other areas within the building. Further, with the recent hurricanes in South Louisiana, the issue of mold, fungus, and mildew remediation became of more interest to those whose homes, buildings, etc, were flooded. The solution for most of these instances has been to use remediation techniques to control or eliminate the microbes.

[0003] However, it would be beneficial to prevent the growth of these microbial organisms, and thus eliminate or minimize the need for remediation. Generally, the prevention of the growth of microbes has been achieved by using building material pre-treated with antimicrobial products. While this technique is effective, it is typically not a solution that will last for the life of the building or structure, and is typically more expensive because of the treatment of the building material. For example, the use of pressure treated or other treated lumber in the construction of a new house is cost prohibitive. Further, many treatments involve the use of heavy metals such as copper, arsenic, etc., which can pose health concerns for those coming in contact with them.

[0004] Therefore, it would be beneficial to the construction industry and home/building owners to have a prophylactic means for treating new and or existing construction to prevent and/or inhibit the growth of unwanted microbial organisms. SUMMARY OF THE INVENTION

[0005] Quaternary ammonium compounds or "quats" for short find use in many industrial applications. Quats are loosely defined as a group of compounds generally having the formula RiR ₂ RsR ₄ -TST ⁺ Y ^" , where the radicals may be the same, different, or part of a ring and Y is a counter anion. Typically, but not always, one of the radicals is a long-chain alkyl group. In most industrial applications, these quat molecules are complexed with a counter ion (anion) to provide for an "active" molecule.

[0006] The inventors hereof have discovered that the use or application of at least one quaternary ammonium compound, sometimes only one, sometimes more than one wherein the more than one contemplates quaternary ammonium compounds having the same or different counter anions, or a prophylactic solution comprising at least one quaternary ammonium compound, sometimes only one sometimes more than one wherein the more than one contemplates quaternary ammonium compounds having the same or different counter anions, can provide for an effective, non-oxidizing prophylactic measure for microbial organisms. In some embodiments, the application of the at least one quaternary ammonium compound or the prophylactic solution can also impart to the one or more articles some flame retardant properties. In some embodiments, the application of the at least one quaternary ammonium compound or the prophylactic solution can also impart to the one or more articles some termite repellant properties. In this embodiment, the one or more articles to which the at least one quaternary ammonium compound or the prophylactic solution is applied must obviously be susceptible to termite damage, i.e. cellulosic substrates such as wood, cotton, paper, or bagassc-bascd building products. Non- limiting examples of these products include ceiling tiles, wooden furniture, wallboards, etc., and the like. By repelling termites, it is meant that the termites do not feed on the quat treated cellulosic material, and in essence may resort to cannibalistic behavior for food or search for a different food source, if one is available, instead of feeding on the quat treated cellulosic material as a food source. [0007] Thus, the present invention relates to a method for the prevention and/or inhibition of microbial organism growth. The method comprises applying to one or more article a quaternary ammonium compound having the formula:

wherein R ₁ , R2, R ₃ , and R ₄ are selected from z ^" ) substituted or unsubstituted alkyl groups or if) substituted or unsubstituted alkenyl groups, wherein if i) or if) is substituted, they have one or more substituent groups selected from aryl, heterocyclyl, hydroxyl, ester, benzyl, carboxyl, halo, nitro, cyano, alkoxy or oxo groups; m is 1, 2, or 3; R5 is selected from i) substituted or unsubstituted alkyl groups or if) substituted or unsubstituted alkenyl groups, wherein iff) or if) is substituted, they have one or more substituent groups selected from aryl, heterocyclyl, hydroxyl, ester, benzyl, carboxyl, halo, nitro, cyano, alkoxy or oxo groups or OH; and X is selected from elements having a net ionic charge of -2; and wherein said one or more articles are present in an environment that can facilitate or encourage the growth of at least one microbial.

[0008] In some embodiments a prophylactic solution comprising at least one quaternary ammonium compound is applied to the one or more article. DETAILED DESCRIPTION OF THE INVENTION

[0009] "Microbial", "microbe" and "microbial organism" can be used interchangeably herein and are used herein in the broadest sense and are meant to include one or more of the following: molds, mildews, funguses, and the like. In some embodiments, the microbial is considered a contaminant to the one or more article(s)

[0010] Thus, by present in an environment that can facilitate or encourage the growth of at least one microbial, it is meant an environment that facilitates or encourages the growth of one or more molds, mildews, funguses, and the like. In some embodiments, these environments are generally moist or humid environments wherein the relative humidity can reach 60% or greater and/or wherein poor ventilation is available, which contributes to moist

or humid conditions. In some embodiments, the environment is also warm, for example, 55 ⁰ F (average temperature) or higher.

[0011] Also, "building" as used herein is also used in its broadest sense and is meant to include homes, office and/or other commercial buildings, storage units or buildings, apartments, mobile homes, travel trailers, detached garages, camps, and the like. [0012] "Construction material" as used herein is also used in its broadest sense and is meant to encompass any material used in the construction of homes and buildings upon which microbial organisms can grow. Thus, "construction material" as used herein is meant to encompass wood, cotton, cardboard, liner board, other similar paper products, composite assemblies, and the like. Articled

[0013] In some embodiments, the one or more articles to which the quaternary ammonium compound or the prophylactic solution is applied is a construction material. In some embodiments, the article can be any one of the following: i) gypsum board; ii) ceiling tiles or other ceiling material made form natural or synthetic materials; iiϊ) particleboard or other similar composite material used in the construction of a building, i.e. fiber board, press-board, and the like; iv) synthetic wood, i.e. synthetic doors molded from resin materials, synthetic moldings, etc; v) carpeting; vii) padding used under carpeting; viii) insulation, be it made from natural or synthetic materials; ix) wood; x) concrete or other similar porous material; xi) porous tiles such as flooring or wall tiles; xii) synthetic materials used in the construction of buildings, i.e. artificial marbles, stones, resins such as fiberglass, etc; xiii) bricks; and ix) any combinations thereof.

[0014] In some embodiments, the article is selected from one or more of the following: curtains, bed sheets, furniture (sofas, chairs, tables, beds, and the like), and the like. Quaternary Ammonium Compound

[0015] It should be noted that the term "quaternary ammonium compound", "quat", or "boron-quat" as used herein refers to a compound in which at least one nitrogen atom is joined to four organic radicals leaving a net positive charge. In certain aspects, the organic radicals can be alkyl or alkenyl (unsaturated alkyls) groups that are linear or branched, substituted or unsubstituted, or mixtures thereof. In other aspects, the term "quaternary ammonium compound" or "quat" is also intended to encompass a compound in which more than one nitrogen is joined to four organic radicals. For example, one of the four organic radicals of a quat may be a "shared" radical with a second quat.

[0016] Generally, the quaternary ammonium compounds used in the present invention can be represented by the formula:

wherein m can be 1, 2, or 3, and X is selected from an element having a net ionic charge of —2, sometimes oxygen ("O").

[0017] The boron-containing quats according to the present differ from those previously disclosed in the art in that they are not complexed with a counter anion. Instead, boron, the active species imparting the desired properties to the quat, is a part of the qxxat molecule, and the anion X providing the ionic charge necessary to provide for a quat having a net ionic charge of 0, which can be suitably selected from elements having a net ionic charge of —2, in some embodiments oxygen, is also part of the boron-containing quat molecule. While not wishing to be bound by theory, the inventors hereof believe that this provides for a more effective quat molecule than previously disclosed because the quat itself has a net ionic charge of zero without the need for a counter anion. Further, the counter anion, the active species imparting the desired properties to the quat, in previously disclosed quats, was held by an ionic bond. However, in the present case, the bond between the boron active species and the quat molecule is a covalent bond. The inventors hereof theorize that exposure to the elements, i.e. wind, rain, washing, pressure washing, etc., of a substrate treated with a quat complexed with a counter anion could cause the ionic bond between the active species, e.g. carbonate, bi-carbonate, etc., to break and another species to be substituted for the active species. For example, in the case of excessive washing with salt water, a Cl ^" ion from the salt in the water may be substituted for the active species complexed with the quat, thus causing

the quat to lose its desired characteristics. However, in the case of the quats according to the present invention the active species is held to the quat by a covalent bond, thus excessive washing would not cause this substitution.

[0018] The five carbon chains, i.e. Ri, R ₂ , R ₃ , R ₄ , and R5 of the quats used in the present invention are independently selected from f) substituted or unsubstituted alkyl groups or if) substituted or unsubstituted alkenyl groups, wherein if f) or if) is substituted, they have one or more substituent groups selected from aryl, heterocyclyl, hydroxyl, ester, benzyl, carboxyl, halo, nitro, cyano, alkoxy or oxo groups. Alkyl and alkenyl groups suitable for use in the quats are those that contain in the range of from 1 to 20 carbon atoms. In some embodiments, Ri , R2, and R ₄ are independently chosen from alkyl groups having in the range of from 1 to 3 carbon atoms, and R ₃ are independently chosen from 6 to 20 carbon atom-containing groups selected from f) substituted or unsubstituted alkyl groups or ii) substituted or unsubstituted alkenyl groups, wherein if i) or ii) is substituted, they have one or more substituent groups selected from aryl, heterocyclyl, hydroxyl, ester, benzyl, carboxyl, halo, nitro, cyano, alkoxy or oxo groups; and m is 1, 2, or 3. In another embodiment, Ri and R ₂ are methyl groups, R ₃ is chosen from alkyl groups having in the range of from 1 to 3 carbon atoms, and R4 is selected from unsubstituted alkyl groups containing in the range of from 8 to 14 carbon atoms. In one embodiment, R ₃ is an unsubstituted alkyl group containing in the range of from 8 to 10 carbon atoms, and R ₃ is an ethyl group. In still other embodiments, R], R2, R ₃ and R) are alkyl groups having in the range of from 1 to 3 carbon atoms, sometimes methyl groups. In some of these embodiments, Rs is OH.

[0019] In other embodiments of the present invention R ₄ , is selected from i) substituted or unsubstituted alkyl groups that contain from 13 to 16, sometimes 14 to 16, sometimes 14, carbon atoms or if) substituted or unsubstituted alkenyl groups that contain from 13 to 16, sometimes 14 to 16, sometimes 14, carbon atoms, wherein if f) or if) is substituted, they have one or more substituent groups selected from aryl, heterocyclyl, hydroxyl, ester, benzyl, carboxyl, halo, nitro, cyano, alkoxy or oxo groups. These carbon chains can be saturated or unsaturated, preferably unsubstituted. In some embodiments, R ₃ can be selected from unsaturated substituted or unsubstituted, preferably unsubstituted, alkyl groups containing from 13 to 16, sometimes 14 to 16, sometimes 14, carbon atoms. In some of these embodiments, Ri , R ₂ , and R ₄ are independently chosen from alkyl groups having from 1 to 4, sometimes 1 to 3, in some embodiments 2 to 4, carbon atoms. In some of these embodiments, R ₅ is OH.

[0020] In another embodiment, m is 2, and one of the four organic radicals of a quat may be a "shared" radical with a second quat. It should be noted that while in this embodiment R ₄ is shown as the shared radical, the shared radical can be any of Ri , R ₂ , Rs, or R ₄ . In this embodiment, the quaternary ammonium compounds used in the practice of the present invention have the general formula:

[0021] In this embodiment, each Ri, R ₂ , R ₃ , R ₄ , and Rs, are as described above, and each X is selected from those elements having an ionic charge of —2, in some embodiments each X is

O.

[0022] In another embodiment m is 3, and one of the four organic radicals of a quat is a

"shared" radical "with a second quat. In this embodiment, the quaternary ammonium compounds used in the practice of the present invention can have the general formula:

[0023] In this embodiment, each Ri, R ₂ , R ₃ , R ₄ , Rs ₅ and X are as described above. It should be noted that while in this embodiment R ₂ and R ₃ are shown as shared radicals, the shared radicals can be any of Ri, R2, R3, or R4.

[0024] The quats of the present invention can be prepared by any methods known in the art, exemplary methods include those described in commonly-owned co-pending applications

PCT US2005/010162 and US 60/730,821, which are incorporated herein by reference in their entirety.

Prophylactic Solutions Containing the Quaternary Ammonium Compound

[0025] While the quat(s) can be applied to the one or more articles directly, it is preferred to apply a prophylactic solution, more preferably an aqueous prophylactic solution, comprising the quaternary ammonium compound to the one or more articles.

[0026] The processes used in the production of quats, for example those described in commonly-owned co-pending applications PCT US2005/010162 and US 60/730,821, typically produce quats in an aqueous solution. The aqueous solution typically comprises water, at least one polar organic co-solvent, and one or more quats, as described herein. Polar organic co-solvents present in these aqueous solutions typically have some compatibility with water since water is typically a component of the aqueous solution. Polar organic co-solvents arc typically selected from several classes of compounds, such as: alcohols, such as methanol, ethanol, isopropyl alcohol, propanol, butanol, isobutyl alcohol, Ci — Ce alcohols, C ₁ — C ₄ alcohols, and the like, with methanol being a preferred example; polyalcohols, such as ethylene glycol, propylene glycol, and the like; esters, such as ethyl acetate, propyl acetate, formates, and the like; ethers, such as methyl tert-butyl ether, dioxane, glymes, and the like;

and carbonyl-containing solvents, such as acetone, acetaldehyde, and the like. It should be noted that in some embodiments, only one polar organic co-solvent is used, and in other embodiments, more than one, sometimes two, or in other embodiments more that two, polar organic co-solvents arc used.

[0027] These aqueous solutions generally have a polar organic co-solvent to water ratio in the range of from about 10:90 up to about 99:1 (wt. co-solvent: wt. water based on the combination of the water and polar organic co-solvent), and the exact amount of the polar organic co-solvent and water is selected according to the selection of Ri, R ₂ , R3 and R ₄ . In general, it is preferred that the ratio of co-solvent : water, by weight and on the same basis, is within the range of from about 50:50 to about 99:1, about 60:40 to about 99:1 is more preferred, about 70:30 to about 98:2 is even more preferred, and about 80:20 to about 95:5 is yet more preferred.

[0028] It has generally been found that aqueous solutions having a higher ratio of co-solvent to water are preferred for quats containing very hydrophobic alkyl substituent groups, e.g., double tailed or twin tailed quats where the alkyl groups are Ci 0 - C20, for example, while aqueous solutions having a lower ratio of co-solvent to water are preferred for boron-quats having less hydrophobic alkyl substituent groups, e.g., a (C2 - Ce) alkyltrimethylammonium salt.

[0029] The aqueous solutions can contain as the polar organic co-solvent an alcohol, and thus, the aqueous solution comprises a mixture of alcohol and water. In this embodiment, it is typically preferred that the aqueous solution comprises a mixture of a Ci - Ce alcohol and water in a ratio of from 10:90 to 99:1, by weight, on the same basis as above. Even more preferred is an aqueous solution that comprises a mixture of a Ci - C ₄ alcohol and water in a ratio of from about 50:50 to about 99:1, about 60:40 to about 99:1 is more preferred, about 70:30 to about 98:2 is even more preferred, and about 80:20 to about 95:5 is yet more preferred, all by weight and on the same basis. A preferred aqueous solution used in the production of quat(s) is a mixture of methanol and water in a ratio of about 85:15, by weight, based on the water and alcohol.

[0030] It should be understood that the aqueous solutions can comprise water, at least one polar organic co-solvent and the quat(s). However, when describing the amount of water and polar organic co-solvent in the aqueous solution, these ratios were based on the amount of polar organic co-solvent and water. Thus, when considering the amounts of these components and the quat in the solution, the mixture is a ternary composition comprising at least three major components, water, polar organic co-solvent, and the quat(s) "salt". Thus,

the ratio of the components of the aqueous solution can be represented as a ratio of wt. quat: wt. polar organic co-solvent: wt. water, based on the aqueous solution. By way of example, an aqueous solution formed by adding 25% by weight of a quat salt to a mixture comprising an 85:15 by weight mixture of methanol: water, would have a ternary composition, by weight, of 25:64:11, quat salt: methanol: water by weight, based on the aqueous solution. [0031] Because of economic and/or process considerations these aqueous solutions generally have a concentration of quat(s) ranging from about 1 to about 50 wt.% quat, based on the aqueous solution. If the quat concentration of the aqueous solution is in the range of from about 1 to about lθwt.%, based on the aqueous solution, then the aqueous solution can be applied to substrates as is, but these aqueous solutions are generally only available with quat concentrations in the range of from about 10 to about 30 wt.%, based on the aqueous solution, of the quat(s), more typically in the range of from about 20 to about 30wt.%, on the same basis. The inventors hereof have discovered that quat(s) concentrations this high are not necessary for providing the desired characteristics to the one or more articles to which they are applied and ranges much lower are effective and less costly. Thus, in the practice of the present invention, a diluent can be added to the aqueous solution to form a prophylactic solution, obviously comprising the diluent and the same components as the aqueous solution, having a quat concentration in the range of from about 1 to about 10 wt.%, in some embodiments in the range of from about 2 to about 8 wt.%, and in some embodiments in the range of about 4 to about 6 wt.%, all based on the prophylactic solution. Diluents suitable for use herein can be selected from polar organic co-solvents, as described above, water, and mixtures thereof. In some embodiments, the diluent is water. Alternative Quaternary Ammonium Compounds

[0032] In some embodiments, one, in some embodiments more than one, quaternary ammonium compound(s) having the formula below can be used:

m

wherein Rj, R ₂ , R ₄ , Rs, X, and m are as described above, R' is a hydrocarbon group having from 1-10 carbon atoms, in some embodiments in the range of from 1 to 5, in some embodiments in the range of from 1 to 3, and R" and R'" are independently selected from z) substituted or unsubstitutcd alkyl groups or if) substituted or unsubstitutcd alkcnyl groups, wherein if z) or U) is substituted, they have one or more substituent groups selected from aryl, heterocyclyl, hydroxyl, ester, benzyl, carboxyl, halo, nitro, cyano, alkoxy or oxo groups. In some embodiments R" and R'" are selected from unsubstituted alkyl groups having in the range of from 1 to 20 carbon atoms, in some embodiments in the range of from 1 to 15, and in other embodiments in the range of from 6 to 14. Application to Articled

[0033] The at least one quaternary ammonium compound, aqueous solution or prophylactic solution, in some embodiments an aqueous solution, in other embodiments an aqueous prophylactic solution, can be applied to the one or more article(s) during any stage of the construction of the building. For instance, they can be applied to the concrete slab when it is complete, to the wall studs as they are put in place, the ceiling joists as they are put in place, the sheet-rock as it is hung, the ceiling tiles as they are in put in place, etc. In some embodiments, the prophylactic solution is applied to the one or more article(s) after the building has been completed. In other embodiments, the prophylactic or aqueous solution is applied to the wall studs, and/or cement, and/or ceiling joists, and/or wood roofing material before they are covered with other materials, i.e. roofing shingles, etc. In this and other embodiments, the prophylactic or aqueous solution can also be applied to other articles such as sheet rock or wall-boards such as paneling, bricks, etc. It is also contemplated that the prophylactic or aqueous solutions containing different quats can be used to achieve desired results. In some embodiments, the at least one quaternary ammonium compound is applied to one, sometimes more than one, sometimes all of the surfaces of the one or more articlc(s). [0034] The method by which the at least one quaternary ammonium compound, aqueous solution or prophylactic solution it is applied to the one or more articles is not critical to the present invention. Non-limiting examples of suitable application methods include coating, dipping, soaking, brushing, spraying, and the like. Because of the nature of most applications, in some embodiments the quaternary ammonium compound is applied through spraying, in some embodiments with a pressure spraying device such as a pressure washer or pressurized spraying system, e.g. a garden sprayer pressurized by hand pumping. [0035] The above description is directed to several embodiments of the present invention. Those skilled in the art will recognize that other embodiments, which are equally effective,

could be devised for carrying out the spirit of this invention. It should also be noted that embodiments of the present invention contemplate that all ranges discussed herein include ranges from any lower amount to any higher amount.