Aqueous coatings containing biosurfactants as bioadjuvants and methods of use thereof

Abstract

To reduce a necessary biocide concentration in a coating or paint composition.SOLUTION: Disclosed is an aqueous coating composition including at least one latex polymer derived from at least one monomer copolymerized or blended with a rhamnolipid and / or sophorolipid biosurfactant, which in one embodiment is a mono-rhamnolipid. Also provided is an aqueous architectural coating composition including at least one latex polymer derived from at least one monomer copolymerized or blended with a biosurfactant, at least one pigment, and water.SELECTED DRAWING: None

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Patent Application No. 62 / 755,738, filed November 5, 2018, which is incorporated herein by reference in its entirety.

[0002] The present invention relates to compositions incorporating biosurfactants for architectural coatings, such as paints, and methods of use thereof. Specifically, the invention relates to the use of biosurfactants as emulsifiers in emulsion polymerization to produce aqueous latex dispersions, aqueous latex coatings, aqueous latex binders, and aqueous latex paints. Furthermore, the invention relates to the use of biosurfactants as additives and / or adjuvants for aqueous latex dispersions, aqueous latex coatings, aqueous latex binders, and aqueous latex paints. Biosurfactants typically comprise rhamnolipids or sophorolipids. [Background technology]

[0003] A paint is any liquid, liquefiable, or mastic composition that converts to a solid film after application to a substrate in a thin layer. It is commonly used to protect, color, or provide texture to an object. Paints contain binders (also known as vehicles or resins), diluents or solvents, pigments or extenders, and may also have other additives. The binder, commonly called the vehicle, is the film-forming component of a paint. It is the only component that must be present. The components listed below are optional, depending on the desired properties of the cured film.

[0004] The binder provides adhesion and also has a significant impact on properties such as gloss, durability, flexibility, and toughness. In latex paints, the binder comprises latex.

[0005] Latex is a stable dispersion of polymeric microparticles in an aqueous medium (a colloidal emulsion). It is therefore a suspension / dispersion of rubber or plastic polymeric microparticles in water. Latex can be natural or synthetic. Polymerization is the preferred technique used to prepare emulsion polymers and polymer latexes.

[0006] Latex paints are water-based dispersions of submicrometer polymer particles. The term "latex" in relation to paints simply refers to the aqueous dispersion, not the source of latex rubber (the sap of rubber trees, historically referred to as latex). The use of latex, produced by emulsion polymerization, in the production of paints or coatings for substrates is well known in the art.

[0007] Latex paints are used in a variety of applications, including interior and exterior finishes and flat, semi-gloss, and gloss applications. Latex paints cure through a process called coalescence, in which first the water, followed by the evaporation of trace or coalescing solvent, pulls the paint together, softening the latex binder particles and fusing them together into an irreversibly bonded network, so that the paint cannot be redissolved in the solvent / water that originally carried it. This is a characteristic of paints that distinguishes them from, for example, water-based desktop inkjet printer inks. However, such paints or coatings are adversely affected by the presence of emulsifiers, which are necessary for the emulsion polymerization process. Furthermore, in latex polymerization, surfactants are necessary to provide a stable monomer pre-emulsion, stability during polymerization, and overall stability of the final latex. Residual surfactants in the paint and the hydrolysis effect of some polymers can leave the paint susceptible to softening and water-induced degradation over time.

[0008] The primary purpose of a thinning agent is to dissolve the polymer and adjust the viscosity of the paint. It is volatile and does not become part of the paint film. It also controls flow and application characteristics and, in some cases, can affect the stability of the paint in its liquid state. Its primary function is as a carrier for nonvolatile components. Thinner oils are needed to apply the heavier oils in oil-based interior house paints (e.g., linseed oil). These volatile substances impart their properties temporarily, and once the solvent evaporates, the remaining paint is fixed to the surface. This component is optional; some paints do not have a thinning agent. Water is the primary thinning agent in water-based paints, even in cosolvent forms. Solvent-based paints, also known as oil-based, can have various combinations of organic solvents as thinning agents, including aliphatics, aromatics, alcohols, ketones, and white spirit. Specific examples are organic solvents such as petroleum distillates, esters, and glycol ethers. In some cases, volatile low-molecular-weight synthetic resins also serve as thinning agents.

[0009] Pigments are particulate solids incorporated into paints to contribute color. Extenders are particulate solids incorporated to impart toughness, texture, special properties to the paint, or reduce the paint's cost. Alternatively, some paints contain dyes instead of or in combination with pigments. Pigments can be classified as either natural or synthetic. Natural pigments include various clays, calcium carbonate, mica, silica, and talc. Synthetic materials include modified molecules, calcined clay, precipitated barium sulfate, precipitated calcium carbonate, and synthetic pyrogenic silica. In the production of opaque paints, hiding pigments also protect the substrate from the harmful effects of ultraviolet light. Hiding pigments include titanium dioxide, phthalo blue, red iron oxide, and many others. Extenders are a specialized type of pigment that thicken the film, support its structure, and increase the volume of the paint. Extenders are typically inexpensive and inert materials such as diatomaceous earth, talc, lime, barite, and clay. Floor paints that are subject to wear may contain fine silica sand as an extender. Not all paints contain extenders, but some paints contain mostly pigment / extenders and a binder.

[0010] In addition to the three main categories of components, paints may have a wide variety of other additives, usually added in small amounts but providing significant benefits to the product. Some examples include additives that modify surface tension, improve flow, improve finished appearance, increase wetted edge, increase pigment stability, provide anti-freeze properties, control foaming, and control skinning. Other types of additives include catalysts, thickeners, stabilizers, emulsifiers, texturizers, adhesion promoters, UV stabilizers, flatteners (de-glossing agents), biocides to combat bacterial growth, and the like. Additives generally do not significantly alter the percentages of the individual components in the formulation. Surfactants are important components of many formulations for a variety of applications.

[0011] In the paint and coating additive market, surfactants and biocides are important components in formulations for a variety of reasons. Surfactants are used as wetting agents, defoamers, and dispersants. Biocides are used to prevent microbial spoilage and protect dried films from mold growth.

[0012] Biocides and fungicides are two classes of antimicrobial agents used in paint cans for two main purposes. Biocides, also known as in-can preservatives, are used to protect the wet paint from deterioration due to bacterial growth, while fungicides are used to protect the dry film from fungal deterioration. Biocides belonging to various classes of chemical structures, such as formaldehyde-releasers, isothiazolinones, carbamates, and thiols, are used for their various properties. Some of the chemical structures are listed as either carcinogens or corrosives and sensitizers.

[0013] Due to water intrusion and building damage caused by typhoons, windstorms, floods, and other similar natural disasters, the use of dry film fungicides or mildewcides has increased. However, in some cases, interior paints for basements, bathrooms, and kitchens in homes, hotel rooms, school buildings, and hospital environments are formulated with mildewcides that are not environmentally friendly or have handling safety issues and can cause sensitization reactions. Surfactants can be classified according to the nature of the charge on the individual polar components. Anionic surfactants are generally negatively charged due to sulfonic acid or sulfur groups. Nonionic surfactants contain no ionic components, and the majority of all nonionics are the polymerization products of 1,2-epoxyethane. Cationic surfactants are characterized by a positively charged quaternary ammonium group. Finally, amphoteric surfactants have both positively and negatively charged moieties in the same molecule. Biosurfactants can also be divided into two categories: (1) low molecular mass molecules with low surface and interfacial tension, and (2) high molecular mass polymers that bind tightly to surfaces. Examples of low molecular mass molecules are rhamnolipids and sophorolipids. Examples of high molecular mass polymers are food emulsifiers and biodispersants. [Prior art documents] [Patent documents]

[0014] [Patent Document 1] US Patent Application Publication No. 2011 / 0270207 [Patent Document 2] US Patent Application Publication No. 2011 / 0237531 Summary of the Invention

[0015] The present invention uses biosurfactants (i.e., having adjuvant or bioadjuvant effects) (including but not limited to monorhamnolipids, dirhamnolipids, and / or sophorolipids) to reduce the required biocide concentration in a coating or paint composition. The present invention uses biosurfactants (i.e., biosurfactants having adjuvant or bioadjuvant effects) (including but not limited to monorhamnolipids, dirhamnolipids, and / or sophorolipids) to reduce the minimum amount of biocide required in a coating or paint composition. In this regard, rhamnolipid and / or sophorolipid biosurfactants are "green" surfactants, possessing advantageous characteristics for coatings or paints.

[0016] The present invention provides processes that use biosurfactants to produce emulsion polymers and the resulting emulsion polymer products. Specifically, the present invention is directed to the use of biosurfactants to synthesize latex binders, paints, and coatings. The biosurfactants can be nonionic or anionic.

[0017] According to the present invention, aqueous coating compositions (eg, latex paints) containing biosurfactants are stable.

[0018] Biosurfactants can be employed in a number of ways in compositions and methods for improving paints and coatings containing latex binders.

[0019] The present invention can employ biosurfactants as surfactants (emulsifiers) during emulsion polymerization to form latex polymers. In another embodiment, the present invention can employ biosurfactants as additives to aqueous dispersions containing latex polymers.

[0020] The aqueous coating composition of the present invention comprises a biosurfactant and at least one latex polymer. The at least one latex polymer in the aqueous coating composition can be pure acrylic, styrene acrylic, vinyl acrylic, or acrylated ethylene vinyl acetate copolymer, more preferably pure acrylic. The at least one latex polymer is preferably derived from at least one acrylic monomer selected from the group consisting of acrylic acid, acrylic acid esters, methacrylic acid, and methacrylic acid esters. For example, the at least one latex polymer may be butyl acrylate / methyl methacrylate copolymer or 2-ethylhexyl acrylate / methyl methacrylate copolymer. Typically, the at least one latex polymer is further derived from one or more monomers selected from the group consisting of styrene, α-methylstyrene, vinyl chloride, acrylonitrile, methacrylonitrile, ureido methacrylate, vinyl acetate, vinyl esters of branched tertiary monocarboxylic acids, itaconic acid, crotonic acid, maleic acid, fumaric acid, ethylene, and C4-C8 conjugated dienes.

[0021] Latex paint formulations typically include additives, such as at least one pigment. In a preferred embodiment of the present invention, the at least one pigment comprises at least one pigment selected from the group consisting of TiO, CaCO, clay, aluminum oxide, silicon dioxide, magnesium oxide, sodium oxide, potassium oxide, talc, barite, zinc oxide, zinc sulfite, and mixtures thereof. More preferably, the at least one pigment comprises TiO, calcium carbonate, or clay.

[0022] In addition to the above components, the aqueous coating composition may include one or more additives selected from the group consisting of dispersants, surfactants, rheology modifiers, antifoaming agents, thickeners, additional biocides, additional fungicides, colorants, waxes, fragrances, and co-solvents.

[0023] In one aspect, described herein is a coating or paint composition containing at least one latex formed from a composition containing at least a biosurfactant.

[0024] The present invention includes a method for preparing an aqueous coating composition using a biosurfactant as an emulsifier or as part of an emulsifier blend. In one embodiment, the biosurfactant is used as an emulsifier during an emulsion polymerization reaction used to produce a latex polymer. The method includes preparing a polymer latex binder using emulsion polymerization by feeding latex monomers to a reactor in the presence of at least one initiator and at least one biosurfactant (emulsifier) compound described above, and polymerizing the latex monomers to produce a latex binder comprising a blend of the latex polymer and the biosurfactant. At least one pigment and other additives can then be mixed with the resulting latex binder to produce the aqueous coating composition. The process of preparing the polymer latex binder may include preparing an initiator solution containing an initiator, preparing a monomer pre-emulsion containing the monomer and a biosurfactant (emulsifier) compound as part of an emulsifier blend, and an optional additional surfactant as a co-emulsifier, adding the initiator solution to a reactor, and adding the monomer pre-emulsion to the reactor.

[0025] When a biosurfactant and optional additional surfactants are employed as an emulsifier or emulsifier blend during emulsion polymerization to form the latex polymer, the latex polymer is prepared from a composition in which the total biosurfactant emulsifier or emulsifier blend (containing the biosurfactant emulsifier and one or more additional surfactants) is 0.5 to 10, preferably 1 to 8, or 2 to 6, or 1.5 to 3 parts by weight per 100 parts by weight of the monomers used to form the binder latex polymer. For example, a pre-emulsion is typically prepared from 0.5% to 6% by weight of the total emulsifier or emulsifier blend, based on the total weight of the monomers used to prepare the binder latex polymer. Generally, two or more surfactants, such as a nonionic surfactant and an anionic surfactant, are used in the emulsion polymerization. In this case, the biosurfactant is the nonionic surfactant. In one embodiment, the emulsifier blend includes a biosurfactant and at least one anionic surfactant. In another embodiment, the emulsifier blend comprises a biosurfactant, at least one anionic surfactant, and at least one nonionic surfactant. In one embodiment, at least 1 wt.%, or at least 2 wt.%, or at least 4 wt.%, or at least 5 wt.%, more typically at least 10 wt.%, or at least 15 wt.%, and even more typically at least 20 wt.%, or at least 30 wt.%, or at least 50 wt.% of the emulsifier blend employed during emulsion polymerization is at least one biosurfactant. In another embodiment, at least 0.1 wt.%, or at least 0.2 wt.%, or at least 0.4 wt.%, or at least 0.5 wt.%, or at least 1.5 wt.%, or at least 2 wt.%, or at least 4 wt.%, or at least 6 wt.%, or at least 8 wt.% of the emulsifier blend employed during emulsion polymerization is at least one biosurfactant. In one embodiment, the biosurfactant is a monorhamnolipid. In another embodiment, the biosurfactant is selected from the group consisting of monorhamnolipids, dirhamnolipids, and sophorolipids. In another embodiment, the biosurfactant comprises monorhamnolipid.

[0026] Suitable anionic emulsifiers include alkali metal alkylarylsulfonates, alkali metal alkyl sulfates, and sulfonated alkyl esters. Specific examples include sodium dodecylbenzenesulfonate, sodium di-sec-butylnaphthalenesulfonate, sodium lauryl sulfate, disodium dodecyldiphenyletherdisulfonate, disodium n-octadecylsulfosuccinamate, and sodium dioctyl sulfosuccinate. Suitable nonionic emulsifiers include, for example, common structures based on polyethylene oxide or oligosaccharide hydrophilic head groups.

[0027] Incorporation of a biosurfactant (emulsifier) compound in the reaction mixture allows the coating composition to have a lower VOC content while maintaining a desirable level of stability of the aqueous coating composition. Incorporation of a biosurfactant (emulsifier) compound in the reaction mixture also allows the coating composition to maintain acceptable biocidal and fungicidal properties while reducing the required concentration of biocides and / or preservatives, where the biosurfactant acts as an adjuvant or bioadjuvant.

[0028] In another embodiment, the biosurfactant is used as an additive to an already formed aqueous latex polymer dispersion or during formulation of a paint or coating composition. (Formulation is the step in which an additive is added to a base aqueous latex polymer dispersion to form the final paint or coating product.) This results in a composition comprising the biosurfactant and the latex polymer. When the biosurfactant is employed as an additive to an already formed latex polymer dispersion, the resulting composition has the biosurfactant in an amount of about 0.001 to 10, e.g., 0.01 to 2, or 0.1 to 0.6 parts by weight per 100 parts by weight of the latex polymer dispersion or total weight of the coating composition (based on the total composition including water). Typically, the amount of biosurfactant added is less than 1% by weight of the composition (less than 10,000 ppm of the composition).

[0029] Optionally, a biosurfactant can be employed as an additive to an already formed latex polymer dispersion. In this embodiment, at least one biosurfactant compound selected from the group consisting of rhamnolipids and sophorolipids is added to an already formed latex polymer dispersion to produce a latex binder. At least one pigment and other additives can then be mixed with the resulting latex binder to produce a paint or aqueous coating composition.

[0030] In another embodiment, the biosurfactants described above are used as additives in the formulation of paint or aqueous coating compositions. When biosurfactants are employed as additives in the formulation of paint or aqueous compositions, such as aqueous latex polymer dispersions, the resulting composition has the biosurfactant in an amount of about 0.001 to 10, e.g., 0.01 to 2, or 0.1 to 0.6 parts by weight per 100 parts by weight of the latex polymer dispersion or total weight of the coating composition (based on the total composition including water). Typically, the amount of biosurfactant added is less than 1% by weight of the composition (less than 10,000 ppm of the composition).

[0031] The method includes adding at least one biosurfactant selected from the group consisting of rhamnolipids and sophorolipids as a bioadjuvant during the formulation of an aqueous latex paint or coating composition to produce the final paint or coating composition. At least one pigment and other additives can be mixed before or after the latex binder to produce the paint or coating composition. Adding the biosurfactant during the formulation of the latex paint or coating composition maintains the stability of the aqueous coating composition at a desired level and provides bioadjuvant properties. That is, incorporating an emulsifier compound, including a biosurfactant, into the reaction mixture can also reduce the required concentration of biocides and / or preservatives while maintaining acceptable biocidal and fungicidal properties of the latex composition or coating composition, where the biosurfactant serves as an adjuvant or bioadjuvant.

[0032] In one embodiment, the biosurfactant, whether utilized as an emulsifier or an additive, comprises at least one monorhamnolipid. In one embodiment, the biosurfactant, whether utilized as an emulsifier or an additive, comprises at least one monorhamnolipid and at least one dirhamnolipid, and optionally at least one sophorolipid.

[0033] In one embodiment, whether utilized as an emulsifier or an additive, the biosurfactant comprises at least one monorhamnolipid and at least one dirhamnolipid, wherein the weight percent ratio of monorhamnolipid to dirhamnolipid is in the range of about 90:10 to 99:1, respectively.

[0034] In one embodiment, whether utilized as an emulsifier or an additive, the biosurfactant comprises at least one monorhamnolipid and at least one dirhamnolipid, wherein the weight percent ratio of monorhamnolipid to dirhamnolipid is in the range of about 85:15 to 99.5:0.5, respectively.

[0035] In one embodiment, whether utilized as an emulsifier or an additive, the biosurfactant comprises at least one monorhamnolipid and at least one dirhamnolipid, wherein the weight percent ratio of monorhamnolipid to dirhamnolipid is in the range of about 80:20 to 99.9:0.1, respectively.

[0036] In one embodiment, whether utilized as an emulsifier or an additive, the biosurfactant comprises at least one monorhamnolipid and at least one dirhamnolipid, wherein the weight percent ratio of monorhamnolipid to dirhamnolipid is in the range of about 50:50 to 99.9:0.1, respectively.

[0037] In one embodiment, whether utilized as an emulsifier or an additive, the biosurfactant comprises at least one monorhamnolipid and at least one dirhamnolipid, wherein the weight percent ratio of monorhamnolipid to dirhamnolipid is in the range of about 40:60 to 99.9:0.1, respectively.

[0038] In one embodiment, monorhamnolipids act as bioadjuvants designed to reduce the required concentration of biocides in coating compositions. When used in emulsion polymerization processes to make latex compositions, incorporating emulsifier compounds, including biosurfactants, in the reaction mixture can also reduce the required concentration of biocides and / or preservatives while maintaining acceptable biocidal and / or fungicidal properties of the latex composition, where the biosurfactant acts as an adjuvant or bioadjuvant.

[0039] In one embodiment, when used as an adjuvant, the biosurfactant does not possess antimicrobial properties.

[0040] In another embodiment, the biosurfactants of the present invention comprise monorhamnolipids which are believed to bind metals and / or nutrients necessary for bacterial growth in a location where metal chelation acts to tie up necessary components of bacterial growth.

[0041] In one embodiment, the biosurfactant, which may be a monorhamnolipid, when used at low levels below the CMC has a neutral or no effect on the growth of a variety of microorganisms.

[0042] In one embodiment, when used at levels (below or near the CMC value), rhamnolipids act to reduce the amount of isothiazolinones required to adequately preserve latex coatings and paints. And finally, with regard to a possible mechanism of action, Solvay provides an abstract and literature citations suggesting that rhamnolipids act, in part, by chelating beneficial metals to microorganisms.

[0043] In one embodiment, the biosurfactants described herein are not active ingredients, but rather compounds that act by physical action to enhance or prolong the activity of an active ingredient. In other words, monorhamnolipids (and mixtures thereof) utilized as adjuvant products act to reduce the amount of biocides (or preservatives) that would otherwise be required to protect paints or coatings from microbial degradation.

[0044] In one embodiment, an effective amount of at least one monorhamnolipid biosurfactant reduces the concentration of biocide required in a coating composition by more than 20%, or 30%, or 40%, or 50% by weight compared to a similar composition without the biosurfactant.

[0045] In one embodiment, an effective amount of at least one monorhamnolipid biosurfactant reduces the concentration of biocide required in a coating composition by more than 60%, 70%, or 80% by weight compared to a similar composition without the biosurfactant. In another embodiment, an effective amount of biosurfactant reduces the concentration of biocide required in a coating composition by more than 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, or 95% by weight compared to a similar composition without the biosurfactant.

[0046] In one embodiment, the effective amount of biosurfactant is less than 5000 ppm, 2000 ppm, 3000 ppm, 1000 ppm, 800 ppm, 500 ppm, 300 ppm, 200 ppm, or 100 ppm of the composition or dispersion.

[0047] In another embodiment, the effective amount of biosurfactant is less than 100 ppm, or 90 ppm, or 80 ppm, or 70 ppm, or 60 ppm of the composition. In yet another embodiment, the effective amount of biosurfactant is from about 1 ppm to about 60 ppm of the composition. In further embodiments, the effective amount of biosurfactant is from about 10 ppm to about 50 ppm of the composition. In another embodiment, the effective amount of biosurfactant is from about 20 ppm to about 50 ppm of the composition. In yet another embodiment, the effective amount of biosurfactant is from about 25 ppm to about 45 ppm of the composition.

[0048] In another embodiment, the effective amount of biosurfactant is less than 5000 ppm, or 4000 ppm, or 3000, or 2000 ppm, or 1000 ppm of the composition.

[0049] In another embodiment, the effective amount of biosurfactant is less than 900 ppm, or 800 ppm, or 500 ppm, or 300 ppm, or 200 ppm of the composition.

[0050] When used in the compositions and methods of the invention, a biosurfactant selected from the group consisting of rhamnolipids and / or sophorolipids may be the only biosurfactant / surfactant. In one embodiment, the compositions of the invention may lack biopolymers, for example, lack dextran.

[0051] The compositions of the present invention may be devoid of polyvinyl alcohol-based block copolymers such as those in the Abstract of Ueno, US Pat. No. 7,348,382 B2.

[0052] In one aspect, (a) at least one latex polymer; (b) a biocide; and (c) a biosurfactant composition, which in one embodiment comprises a monorhamnolipid in an amount effective to reduce the concentration of biocide required in the coating composition compared to a similar composition that does not contain the biosurfactant; (d) water.

[0053] In another aspect, described herein is a process for using a biosurfactant composition during emulsion polymerization, comprising polymerizing a reaction mixture to prepare a latex polymer, the reaction mixture comprising at least one monomer and at least one biosurfactant composition. In one embodiment, the biosurfactant composition comprises monorhamnolipid.

[0054] In yet another aspect, described herein is a method of preparing an aqueous coating composition comprising contacting at least one aqueous dispersion of latex polymer comprising at least one biosurfactant with at least one biocide, wherein the biosurfactant is present in an amount effective to reduce the concentration of biocide required in the coating composition compared to a similar composition without the biosurfactant. In one embodiment, the biosurfactant comprises monorhamnolipid.

[0055] These and other features and advantages of the present invention will become more readily apparent to those of ordinary skill in the art after consideration of the following detailed description, which describes both preferred and alternative embodiments of the invention. [Brief explanation of the drawings]

[0056] [Figure 1] Figure 1 [Figure 2] Figure 2 [Figure 3] Figure 3 [Figure 4] Figure 4 [Figure 5] Figure 5 [Figure 6] Figure 6 DETAILED DESCRIPTION OF THE INVENTION

[0057] The present invention relates to the use of a specific family of biosurfactants for latex dispersions, binders, paints, and coatings. The present invention provides aqueous compositions, e.g., aqueous coating compositions, that have low VOC content comparable to conventional aqueous coating compositions and beneficial biocide and fungicide properties. The aqueous compositions of the present invention are aqueous polymer dispersions containing at least one latex polymer copolymerized or blended with a specific family of biosurfactants, e.g., rhamnolipids. The paints or other aqueous coatings of the present invention typically further contain at least one pigment. Typically, the latex has a Tg below 10°C, more typically below 5°C, and even more typically within the range of 5 to -10°C, e.g., 0°C.

[0058] Members of certain families of biosurfactants can be employed in a number of ways to improve latex aqueous dispersions, binders, coatings, and paints. The present invention can employ biosurfactants as (1) surfactants (emulsifiers) present during latex polymer formation, and / or (2) additives to aqueous dispersions, binders, coatings, or paints containing latex polymers or copolymers.

[0059] As used herein, the term "alkyl" refers to a monovalent straight or branched chain saturated hydrocarbon radical, more typically a monovalent straight or branched chain saturated (C1-C6) alkyl radical, such as, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, hexyl, octyl, hexadecyl, octadecyl, eicosyl, behenyl, tricontyl, and tetracontyl. 40 ) means a hydrocarbon radical.

[0060] As used herein, the term "alkoxyl" refers to an oxy radical substituted with an alkyl group, such as, for example, methoxyl, ethoxyl, propoxyl, isopropoxyl, or butoxyl, which may optionally be further substituted on one or more carbon atoms of the radical.

[0061] As used herein, the term "alkoxyalkyl" refers to an alkyl radical substituted with one or more alkoxy substituents, more typically (C1-C6), such as methoxymethyl, and ethoxybutyl. 22 ) alkyloxy-(C1-C6) alkyl radical.

[0062] As used herein, the term "alkenyl" refers to an unsaturated straight or branched chain hydrocarbon radical, more typically an unsaturated straight, branched chain (C2-C6) containing one or more carbon-carbon double bonds, such as, for example, ethenyl, n-propenyl, iso-propenyl, etc. 22 ) means a hydrocarbon radical.

[0063] As used herein, the terms "aqueous medium" and "aqueous media" are used herein to refer to any liquid medium in which water is the major constituent. Thus, the term encompasses water per se, as well as aqueous solutions and dispersions.

[0064] As used herein, the term "aryl" means a monovalent unsaturated hydrocarbon radical containing one or more six-membered carbocyclic rings, where the unsaturation may be represented by three conjugated double bonds and may be substituted on one or more of the ring carbons with hydroxy, alkyl, alkoxyl, alkenyl, halo, haloalkyl, monocyclic aryl, or amino, such as, for example, phenyl, methylphenyl, methoxyphenyl, dimethylphenyl, trimethylphenyl, chlorophenyl, trichloromethylphenyl, triisobutylphenyl, tristyrylphenyl, and aminophenyl.

[0065] As used herein, the term "aralkyl" refers to an alkyl group substituted with one or more aryl groups, more typically one or more (C-C) aryl groups such as, for example, phenylmethyl, phenylethyl, and triphenylmethyl. 14 ) substituted with aryl substituents (C1-C 18 ) alkyl.

[0066] As used herein, the term "aryloxy" refers to an oxy radical substituted with an aryl group, for example, phenyloxy, methylphenyloxy, isopropylmethylphenyloxy, and the like.

[0067] The term "biopolymer" includes polysaccharides, such as dextrans, proteins, and polyesters, and combinations thereof.

[0068] As used herein, the term "(C x ~C y )" (where x and y are each integers) indicates that the group can contain from x carbon atoms to y carbon atoms per group.

[0069] As used herein, the term "cycloalkenyl" refers to an unsaturated hydrocarbon radical, typically an unsaturated (C5-C6) alkyl group, containing one or more cyclic alkenyl rings, such as cyclohexenyl, cycloheptenyl, etc., and optionally substituted on one or more carbon atoms of the ring with one or two (C1-C6) alkyl groups per carbon atom. 22 ) hydrocarbon radical, and "bicycloalkenyl" refers to a cycloalkenyl ring system containing two fused rings, such as bicycloheptenyl.

[0070] As used herein, the term "cycloalkyl" refers to a saturated hydrocarbon radical, more typically a saturated (C5-C6) alkyl group, containing one or more cyclic alkyl rings, e.g., cyclopentyl, cycloheptyl, cyclooctyl, etc., and optionally substituted on one or more carbon atoms of the ring with one or two (C1-C6) alkyl groups per carbon atom. 22 ) hydrocarbon radical, and "bicycloalkyl" refers to a cycloalkyl ring system containing two fused rings, such as bicycloheptyl.

[0071] As used herein, the critical micelle concentration (CMC) is the concentration of surfactant above which micelles are formed and any additional surfactant added to the system transitions to micelles. Before the CMC is reached, the surface tension varies significantly with surfactant concentration, while after the CMC is reached, the surface tension remains relatively constant or changes at a slower rate.

[0072] As used herein, an indication that a composition is "free" of a particular material means that the composition does not contain any measurable amount of that material.

[0073] As used herein, the term "heterocyclic" means a saturated or unsaturated organic radical containing a ring or fused ring system, such as, for example, thiophenyl, benzothiphenyl, thianthrenyl, pyranyl, benzofuranyl, xanthenyl, pyrrolidinyl, pyrrolyl, pyrazinyl, pyrimazinyl, pyridazinyl, indolyl, quinonyl, carbazolyl, phenathrolinyl, thiazolyl, oxazolyl, phenoxazinyl, or phosphabenzenyl, and typically containing 4 to 16 ring atoms per ring or ring system, including carbon atoms and at least one heteroatom, such as, for example, O, N, S, or P, which may be optionally substituted on one or more of the ring atoms.

[0074] As used herein, the term "hydroxyalkyl" refers to an alkyl radical, more typically substituted with one or more hydroxyl groups (C1-C6), such as, for example, hydroxymethyl, hydroxyethyl, hydroxypropyl, and hydroxydecyl. 22 ) alkyl radical.

[0075] As used herein, the term "(meth)acrylate" collectively and alternatively refers to acrylates and methacrylates, and the term "(meth)acrylamide" collectively and alternatively refers to acrylamides and methacrylamides, so, for example, "butyl (meth)acrylate" refers to butyl acrylate and / or butyl methacrylate.

[0076] As used herein, "molecular weight" in reference to a polymer or any portion thereof refers to the weight average molecular weight ("M w "), where M of the polymer wis a value measured by gel permeation chromatography using aqueous or organic eluents (e.g., dimethylacetamide, dimethylformamide, etc.) depending on the polymer composition, light scattering (DLS or MALLS), viscometry, or many other standard techniques, and is also a value measured by the M of a portion of the polymer. w is a value calculated according to known techniques from the amounts of monomer, polymer, initiator, and / or transfer agent used to make the moiety.

[0077] As used herein, references to a radical being "optionally substituted" or "optionally further substituted" generally mean, unless further limited explicitly or by the context of such reference, that such radical may be substituted with one or more inorganic or organic substituents, such as, for example, alkyl, alkenyl, aryl, aralkyl, alkaryl, heteroatom, or heterocyclyl, or with one or more functional groups capable of coordinating to a metal ion, such as hydroxyl, carbonyl, carboxyl, amino, imino, amide, phosphonic acid, sulfonic acid, or arsenate, or inorganic and organic esters thereof, e.g., sulfate or phosphate, or salts thereof.

[0078] As used herein, an indication that a composition is "substantially free" of a particular substance means that the composition contains only an insubstantial amount of that substance, where "insubstantial amount" means an amount that does not measurably affect the desired properties of the composition.

[0079] As used herein, the term "surfactant" means a compound that reduces surface tension when dissolved in water.

[0080] By "effective amount" is meant the amount of biosurfactant required to reduce the concentration of the biocide, or the minimum amount of biosurfactant required to reduce the concentration of the biocide.

[0081] By "surfactant effective amount" is meant an amount of surfactant that provides a surfactant effect to enhance emulsion stability of the polymer.

[0082] As used herein, the term "architectural coating" is intended to encompass a mixture of resin, optionally pigment, and a suitable liquid vehicle that is reasonably flowable and provides a thin, adherent layer when applied to a substrate. Thus, the term "architectural coating" is intended to encompass paints, lacquers, varnishes, base coatings, clear coatings, primers, and the like.

[0083] Paints that dry by evaporation of the solvent and contain a solid binder dissolved in the solvent are known as lacquers. A solid film is formed when the solvent evaporates, but this film can be redissolved in the solvent, making lacquers unsuitable for applications where chemical resistance is important.

[0084] Latex paints are water-based dispersions of submicrometer polymer particles. The term "latex" in relation to paints simply refers to the aqueous dispersion, not the latex rubber (historically called latex, the sap of rubber trees). These dispersions are prepared by emulsion polymerization. Latex paints cure through a process called coalescence, in which first the water, followed by the evaporation of trace or coalescing solvent, pulls the particles together, softening the latex binder particles and fusing them together into an irreversibly bonded network, so that the paint cannot be redissolved in the solvent / water that originally carried it. Residual surfactants in the paint, and the hydrolysis effect of some polymers, leave the paint susceptible to softening and degradation by water over time.

[0085] emulsion polymerization In a first embodiment, rhamnolipid and / or sophorolipid (also known as sophoroselipid) biosurfactants are used as emulsifiers during the emulsion polymerization reaction used to produce the latex polymer.

[0086] Emulsion polymerization is described in G. Pohlein, "Emulsion Polymerization," Encyclopedia of Polymer Science and Engineering, vol. 6, pp. 1-51 (John Wiley & Sons, Inc., NY, NY, 1986), the disclosure of which is incorporated herein by reference. Emulsion polymerization is a heterogeneous reaction process in which an unsaturated monomer or monomer solution is dispersed in a continuous phase with the aid of an emulsifier system and polymerized with a free radical or redox initiator. The product, a colloidal dispersion of polymer or polymer solution, is called a latex or latex dispersion.

[0087] Monomers typically employed in emulsion polymerization include monomers such as methyl acrylate, ethyl acrylate, methyl methacrylate, butyl acrylate, 2-ethylhexyl acrylate, other acrylates, methacrylates, and blends thereof, acrylic acid, methacrylic acid, styrene, vinyl toluene, vinyl acetate, vinyl esters of carboxylic acids higher than acetic acid, such as vinyl versatate, acrylonitrile, acrylamide, butadiene, ethylene, vinyl chloride, and the like, and mixtures thereof, which are discussed in more detail below in the section entitled "Latex Monomers."

[0088] In the above process, suitable initiators, reducing agents, catalysts, and surfactants are well known in the art of emulsion polymerization. Typical initiators include ammonium persulfate (APS), hydrogen peroxide, sodium, potassium, or ammonium peroxydisulfate, dibenzoyl peroxide, lauryl peroxide, di-tert-butyl peroxide, 2,2'-azobisisobutyronitrile, t-butyl hydroperoxide, benzoyl peroxide, etc. Commonly used redox initiation systems are described, for example, by ASSarac, Progress in Polymer Science 24 (1999), 1149-1204.

[0089] Suitable reducing agents are those that increase the rate of polymerization and include, for example, sodium bisulfite, sodium hydrosulfite, sodium formaldehyde sulfoxylate, ascorbic acid, isoascorbic acid, and mixtures thereof.

[0090] Suitable catalysts are compounds that increase the rate of polymerization and, in combination with the reducing agent described above, promote the decomposition of the polymerization initiator under reaction conditions. Suitable catalysts include, for example, transition metal compounds such as ferrous sulfate heptahydrate, ferrous chloride, copper sulfate, cupric chloride, cobalt acetate, cobaltous sulfate, and mixtures thereof.

[0091] Rhamnolipids are biosurfactants consisting of one or two L-rhamnose units linked to one or two β-hydroxy fatty acids. Thus, rhamnolipid mixtures can contain up to four homologs in different ratios depending on various conditions. The present invention's discoveries relate to the use of these preferred homologs as adjuvants to conventional biocides, in a manner that surprisingly helps reduce the amount of biocide required to kill microorganisms. For example, di-rhamno-mono-lipids exhibited poor adjuvant properties, while mono-rhamno-mono-lipids exhibited excellent potentiation. These findings suggest that in rhamnolipid mixtures, only certain homologs actually contribute to the adjuvant properties.

[0092] However, in some embodiments, for some types of microorganisms (which term encompasses at least certain bacteria and fungi mold), a synergistic effect exists when monorhamnolipids and dirhamnolipids are mixed.

[0093] Emulsion polymerization occurs in the presence of an emulsifier. The biosurfactant monomer is added as an emulsifier in an amount effective to enhance the stability of the polymer emulsion, with or without additional emulsifiers. The rhamnolipid and / or sophoroselipid (also known as sophorolipid) biosurfactant may be the sole emulsifier or may be employed with additional emulsifiers (as co-emulsifiers) other than the rhamnolipid and / or sophoroselipid biosurfactant.

[0094] When a biosurfactant and optional additional surfactants are employed as an emulsifier or emulsifier blend during emulsion polymerization to form the latex polymer, the latex polymer is prepared from a composition in which the total biosurfactant emulsifier or emulsifier blend (containing the biosurfactant emulsifier and one or more additional surfactants) is 0.5 to 10, preferably 1 to 8, or 2 to 6, or 1.5 to 3 parts by weight per 100 parts by weight of the monomers used to form the binder latex polymer. For example, a pre-emulsion is typically prepared from 0.5% to 6% by weight of the total emulsifier or emulsifier blend, based on the total weight of the monomers used to prepare the binder latex polymer. Generally, two or more surfactants, such as a nonionic surfactant and an anionic surfactant, are used in the emulsion polymerization. In this case, the biosurfactant is the nonionic surfactant. In one embodiment, the emulsifier blend includes a biosurfactant and at least one anionic surfactant. In another embodiment, the emulsifier blend comprises a biosurfactant, at least one anionic surfactant, and at least one nonionic surfactant. Typically, at least 1 wt.%, or at least 2 wt.%, or at least 4 wt.%, or at least 5 wt.%, more typically at least 10 wt.%, or at least 15 wt.%, and even more typically at least 20 wt.%, or at least 30 wt.%, or at least 50 wt.% of the emulsifier blend employed during emulsion polymerization is the at least one biosurfactant.

[0095] Typical optional additional emulsifier is the ionic or nonionic surfactant that can be polymerized or non-polymerized during polymerization.Suitable ionic and nonionic surfactants include alkyl polyglycol ethers such as the ethoxylated products of lauryl, tridecyl, oleyl and stearyl alcohol; alkylphenol polyglycol ethers such as the ethoxylated products of octyl or nonylphenol, diisopropylphenol, triisopropylphenol; alkali metal or ammonium salts of alkyl, aryl or alkylaryl sulfonates, sulfates, phosphates, etc., such as sodium lauryl sulfate, sodium octylphenol glycol ether sulfate, sodium dodecylbenzenesulfonate, sodium lauryl diglycol sulfate and ammonium tritertiary butylphenol and penta- and octaglycol sulfonates; sulfosuccinate salts such as disodium ethoxylated nonylphenol half ester of sulfosuccinic acid, disodium n-octyldecyl sulfosuccinate, sodium dioctyl sulfosuccinate, etc.

[0096] In one embodiment, anionic emulsifiers include alkali metal alkylarylsulfonates, alkali metal alkyl sulfates, and sulfonated alkyl esters. Specific examples include sodium dodecylbenzenesulfonate, sodium di-sec-butylnaphthalenesulfonate, sodium lauryl sulfate, disodium dodecyldiphenyletherdisulfonate, disodium n-octadecylsulfosuccinamate, and sodium dioctyl sulfosuccinate. In a further embodiment, nonionic emulsifiers include common structures based on, for example, polyethylene oxide or oligosaccharide hydrophilic head groups.

[0097] The polymer latex or polymer latex binder can be produced by first preparing an initiator solution containing an initiator and water. A monomer pre-emulsion is also prepared containing at least a portion of one or more surfactants, monomers, water, and additional additives such as NaOH and chain transfer agents. The one or more surfactants in the monomer pre-emulsion include a biosurfactant and the optional additional surfactants described above.

[0098] Thus, a typical process for emulsion polymerization preferably involves charging water to a reactor and feeding a monomer pre-emulsion and an initiator solution as separate streams. Specifically, polymer latex binders can be prepared using emulsion polymerization by feeding the monomers used to form the latex binder to a reactor in the presence of at least one initiator and at least one biosurfactant, and polymerizing the monomers to produce the latex binder. Typically, the initiator solution and monomer pre-emulsion are added continuously to the reactor over a predetermined period of time (e.g., 1.5 to 5 hours), causing polymerization of the latex monomers to produce the latex polymer.

[0099] A seed latex, such as a polystyrene seed latex, may be added to the reactor before adding the initiator solution and monomer pre-emulsion. For example, a small amount of the pre-emulsion and a portion of the initiator may be initially charged at the reaction temperature to form a "seed" latex. The "seed" latex procedure provides better particle size reproducibility.

[0100] Under "normal" initiation conditions, where the initiator is activated by heat, polymerization is typically carried out at about 60-90°C. For example, a typical "normal" initiation process can employ ammonium persulfate as the initiator at a reaction temperature of 80±2°C. Under "redox" initiation conditions, where the initiator is activated by a reducing agent, polymerization is typically carried out at about 60-70°C. The reducing agent is typically added as a separate solution. For example, a typical "redox" initiation process can employ potassium persulfate as the initiator and sodium metabisulfite as the reducing agent at a reaction temperature of 65±2°C.

[0101] The reactor is operated at the desired reaction temperature until at least all of the monomers have been fed to produce the polymeric latex binder. Once the polymeric latex binder is prepared, it is preferably chemically stripped to reduce its residual monomer content. Preferably, the polymeric latex binder is chemically stripped by continuously adding an oxidizing agent, such as a peroxide (e.g., t-butyl hydroperoxide), and a reducing agent (e.g., acetone sodium bisulfite), or another redox couple, such as those described by ASSarac, Progress in Polymer Science 24 (1999), 1149-1204, to the latex binder at an elevated temperature for a predetermined period of time (e.g., 0.5 hours). Subsequently, after the chemical stripping step, the pH of the latex binder may be adjusted and other additives may be added.

[0102] In the emulsion, the polymer preferably exists as roughly spherical particles having a diameter of about 50 nanometers to about 500 nanometers dispersed in water.

[0103] The monomers fed to the reactor to prepare the polymer latex binder preferably include at least one acrylic monomer selected from the group consisting of acrylic acid, acrylic acid esters, methacrylic acid, and methacrylic acid esters. Additionally, the monomers may include styrene, vinyl acetate, or ethylene. The monomers may also include one or more monomers selected from the group consisting of styrene, (α)-methylstyrene, vinyl chloride, acrylonitrile, methacrylonitrile, ureido methacrylate, vinyl acetate, vinyl esters of branched tertiary monocarboxylic acids, itaconic acid, crotonic acid, maleic acid, fumaric acid, and ethylene. C4-C8 conjugated dienes such as 1,3-butadiene, isoprene, or chloroprene may also be included. Preferably, the monomers include one or more monomers selected from the group consisting of n-butyl acrylate, methyl methacrylate, styrene, and 2-ethylhexyl acrylate.

[0104] Monomers commonly used in the manufacture of acrylic paints include butyl acrylate, methyl methacrylate, and ethyl acrylate. In acrylic paint compositions, the polymer consists of one or more esters of acrylic or methacrylic acid, typically a mixture, for example, about 50 / 50 by weight of a high Tg monomer (e.g., methyl methacrylate) and a low Tg monomer (e.g., butyl acrylate), with a minor proportion, for example, about 0.5% to about 2% by weight, of acrylic or methacrylic acid. Vinyl-acrylic paints typically contain vinyl acetate and butyl acrylate, and / or 2-ethylhexyl acrylate, and / or vinyl versatate. In vinyl-acrylic paint compositions, at least 50% of the polymer formed consists of vinyl acetate, with the remainder selected from esters of acrylic or methacrylic acid. Styrene / acrylic polymers are typically similar to acrylic polymers, but with all or part of the methacrylate monomers replaced by styrene.

[0105] The latex polymer dispersion (used interchangeably herein with the term "latex dispersion") preferably comprises about 30 to about 75% solids and an average latex particle size of about 70 to about 650 nm. The latex polymer is preferably present in the aqueous coating composition in an amount of about 5 to about 60% by weight, more preferably about 8 to about 40% by weight (i.e., weight percentage of dry latex polymer based on the total weight of the coating composition).

[0106] The aqueous coating compositions are stable fluids that can be applied to a wide variety of materials, such as paper, wood, concrete, metal, glass, ceramic, plastic, plaster, and roofing substrates, e.g., asphalt coatings, roofing felt, foamed polyurethane insulation, or to previously painted, primed, undercoated, worn, or weathered substrates. The aqueous coating compositions of the present invention can be applied to materials by a variety of techniques well known in the art, such as, for example, brush, roller, mop, air-assisted or airless spray, electrostatic spray, etc.

[0107] Rhamnolipids: Rhamnolipid biosurfactants are surface-active compounds released by microorganisms. They are biodegradable, non-toxic, and environmentally friendly materials. Their production depends on fermentation conditions, environmental factors, and nutrient availability. Biosurfactants are extracted from cell-free supernatants using a solvent extraction procedure.

[0108] Rhamnolipids were produced using Pseudomonas aeruginosa DSI0-129 (Rahman et al., 2002a, b, 2003). Rhamnolipids can also be produced from Pseudomonas sp., Serratia rubidea, according to Pattanathu, Production, Characterization and Applications of Biosurfactants - Review, Biotechnology 7(2):360-370, 2008, ISSN 1682-296X (2008) Asian Network for Scientific Information.

[0109] Rhamnolipid biosurfactants, secreted by Pseudomonas aeruginosa, are naturally occurring extracellular glycolipids found in soil and on plants. They offer antibacterial and antifungal activity and low toxicity levels.

[0110] Rhamnolipids have been used in the medical field to combat certain types of bacteria, viruses, and fungi. U.S. Patent Application Publication No. 2011 / 0270207A1 to DeSanto discloses rhamnolipid-based formulations that disinfect, sanitize, deodorize, and act as antibacterial and antifungal agents for living and working environments. Furthermore, the publication discloses the use of rhamnolipids to create biofilms that prevent bacterial and fungal growth when applied to surfaces. This technique has been determined to be useful for creating clean surface areas during medical procedures, chemical analysis, food preparation, and for daycare facilities and hospitals. Rhamnolipid biosurfactants produced by Pseudomonas aeruginosa DS10-129 have shown important applications in the bioremediation of hydrocarbons in gasoline-spill soils and petroleum oily sludge. Rhamnolipid biosurfactants enhance the bioremediation process by releasing weathered oils from the soil matrix and also enhance the bioavailability of hydrocarbons for microbial degradation. This has potential applications in the remediation of hydrocarbon-contaminated sites. The biosurfactant rhamnolipid is an EPA-registered product for use as a biofungicide in agricultural applications.

[0111] Bacteria of the genus Pseudomonas are known to produce glycolipid surfactants containing rhamnose and 3-hydroxy fatty acids (Lang and Wullbrandt, 1999; Rahman et al., 2002b). Rhamnolipids produced by Pseudomonas aeruginosa have been extensively studied, and the homologous RL1 (RhC) 10 C 10 ,), RL2(RhC 10 ,), RL3(Rh2C 10 C 10 ), and RL4(Rh2C 10Rhamnolipids have been reported as mixtures of rhamnolipids (Syldatk and Wagner, 1987; Lang and Wagner, 1987; Rahman et al., 2002b) using virgin olive oil (Healy et al., 1996). Rhamnolipids were produced by Pseudomonas fluorescens NCIMB11712, a methylpentose monosaccharide. Disaccharide rhamnolipids are formed by condensing two moles of rhamnose sugar, with an acetal group attached to the hydrophobic group. However, the lipid portion of the molecule contains ester and carboxyl groups. Rhamnolipids produced by Pseudomonas aeruginosa are among the most effective surfactants when applied to remove hydrophobic compounds from contaminated soil (Rahman et al., 2006). These have a high solubility (30–32 mN m−1) of rhamnolipids (30–32 mN m−1). -1 Low average minimum surface tension (10.4~15.5U mL -1 High average emulsifying activity of the filtrate, low critical micelle concentration (CMC) (5-65 mg L -1 ), and has a high affinity for hydrophobic organic molecules (Van Dyke et al., 1993).

[0112] Structural Formula I shows the structure of a typical monorhamnolipid, RLL, or R1 (α-L-rhamnopyranosyl-β-hydroxydecanoyl-β-hydroxydecanoate, C26H48O9 (504 g / mol). [ka]

[0113] Structure II shows the structure of a typical dirhamnolipid, RRLL, or R2 (2-O-α-L-rhamnopyranosyl-α-L-rhamnopyranosyl-β-hydroxydecanoyl-β-hydroxydecanoate, C32H58O13 (650 g / mol): [ka]

[0114] As mentioned above, there are two main groups of rhamnolipids: monorhamnolipids and dirhamnolipids.

[0115] Monorhamnolipids have a single rhamnose sugar ring. The basic formula (most often produced by P. aeruginosa) is: C 26 H 48 L-rhamnosyl-β-hydroxydecanoyl-β-hydroxydecanoate (Rha-C) with the formula O9 10 -C 10 Its IUPAC name is 3-[3-[(2R,3R,4R,5R,6S)-3,4,5-trihydroxy-6-methyloxan-2-yl]oxydecanoyloxy]decanoic acid.

[0116] Dirhamnolipids have two rhamnose sugar rings. The basic formula is: C 32 H 58 O 13 L-rhamnosyl-L-rhamnosyl-β-hydroxydecanoyl-β-hydroxydecanoate (Rha-Rha-C) has the formula 10 -C 10 Its IUPAC name is 3-[3-[4,5-dihydroxy-6-methyl-3-(3,4,5-trihydroxy-6-methyloxan-2-yl)oxyoxan-2-yl]oxydecanoyloxy]decanoic acid.

[0117] Some other forms or names of more common dirhamnolipids include: L-rhamnopyranosyl-L-rhamnopyranosyl-β-hydroxydecanoyl-β-hydroxydecanoate (Rha-C 10 -C 10 (often referred to as L-rhamnopyranosyl-L-rhamnopyranosyl-β-hydroxydecanoyl-β-hydroxydodecanoate (Rha-Rha-C) 10 -C 12(often referred to as L-rhamnopyranosyl-L-rhamnopyranosyl-β-hydroxytetradecanoyl-β-hydroxytetradecanoate (Rha-Rha-C 14 -C 14 often referred to as).

[0118] Further specific nomenclature for rhamnolipids includes: Decanoic acid, 3-[[6-deoxy-2-O-(6-deoxy-α-L-mannopyranosyl)-α-L-mannopyranosyl]oxy]-, 1-(carboxymethyl)octyl ester 1-(carboxymethyl)octyl 3-[(6-deoxy-α-L-mannopyranosyl)oxy]decanoate, 3-[3'-(L-rhamnopyranosyloxy)decanoyloxy]decanoic acid 3-[3'-(2''-O-α-L-rhamnopyranosyl-α-L-rhamnopyranosyloxy))decanoyloxy]decanoic acid

[0119] Rhamnolipids are found with the following combinations of fatty acids: Hydroxyoctanoyl=C8 Hydroxydecanoyl=C 10 Hydroxydecanoate = C 10 Hydroxydodecanoyl=C 12 Hydroxydodecanoate = C 12 Hydroxytetradecanoyl=C 14 Hydroxytetradecanoate = C 14

[0120] The total number of carbon atoms is the same, but C 10 -C 12 C 12 -C 10 Compounds that are switched to are called structural isomers, which means that the formula is the same in both molecules, but the bonds or links are connected differently.

[0121] In various publications, instead of monorhamnolipid as Rha-, it is sometimes abbreviated as Rh or RL2. Similarly, instead of Rha-Rha- to designate dirhamnolipid, Rh-Rh- or RL1 is used. For historical reasons, "rhamnolipid 2" is monorhamnolipid and "rhamnolipid 1" is dirhamnolipid. This, in fact, leads to some ambiguity in the usage in the literature, i.e., "RL1" and "RL2." For purposes of this specification, "rhamnolipid 1" or "RL1" is monorhamnolipid and "rhamnolipid 2" or "RL2" is dirhamnolipid.

[0122] In various studies, the following rhamnolipids have been detected as being produced by the following bacteria: 12:1 , C 14:1 refers to a fatty acyl chain with a double bond).

[0123] Rhamnolipids (monorhamnolipids) produced by P. aeruginosa: Rha-C8-C 10 , Rha-C 10 -C8, Rha-C 10 -C 10 , Rha-C 10 -C 12 , Rha-C 10 -C 12:1 , Rha-C 12 -C 10 , Rha-C 12:1 -C 10

[0124] Rhamnolipids (dirhamnolipids) produced by P. aeruginosa: Rha-Rha-C8-C 10 , Rha-Rha-C8-C 12:1 , Rha-Rha-C 10 -C8, Rha-Rha-C 10 -C 10 , Rha-Rha-C 10 -C 12:1 , Rha-Rha-C10 -C 12 , Rha-Rha-C 12 -C 10 , Rha-Rha-C 12:1 -C 12 , Rha-Rha-C 10 -C 14:1

[0125] Rhamnolipids produced by P. aeruginosa (not identified as either monorhamnolipids or dirhamnolipids): C8-C8, C8-C 10 , C 10 -C8, C8-C 12:1 , C 12:1 -C8, C 10 -C 10 , C 12 -C 10 , C 12:1 -C 10 , C 12 -C 12 , C 12:1 -C 12 , C 14 -C 10 , C 14:1 -C 10 , C 14 -C 14 .

[0126] Rhamnolipids produced by P. chlororaphis (monorhamnolipids only): Rha-C 10 -C8, Rha-C 10 -C 10 , Rha-C 12 -C 10 , Rha-C 12:1 -C 10 , Rha-C 12 -C 12 , Rha-C 12:1 -C 12 , Rha-C 14 -C 10 , Rha-C 14:1 -C 10

[0127] Rhamnolipids produced by Burkholdera pseudomallei (dirhamnolipids only): Rha-Rha-C 14 -C 14

[0128] Rhamnolipids produced by Burkholdera (Pseudomonas) plantarii (dirhamnolipids only): Rha-Rha-C 14 -C 14

[0129] Rhamnolipid preparations for use as emulsifiers or additives in the present invention may be crude rhamnolipids or highly purified rhamnolipids. Crude rhamnolipid preparations contain rhamnolipids with many extraneous impurities and / or a wide variety of rhamnolipid mixtures, which reduces their effectiveness in formulations. Highly purified rhamnolipid preparations contain rhamnolipids from which extraneous impurities have been removed and / or the rhamnolipids have been purified to meet specific parameters that increase their effectiveness in formulations containing dirhamnolipid, monorhamnolipid, or specific mixtures of both.

[0130] Rhamnolipid formulations are produced by removing unwanted impurities from the initial mixture, subsequently establishing the percentage and type of rhamnolipid present in the final mixture, and simply diluting the rhamnolipid preparation with a carrier or diluent, preferably water or ethanol. The present invention is not limited to the use of water and ethanol as a carrier or diluent. The present invention contemplates the use of any carrier or diluent so long as it is compatible with the rhamnolipid.

[0131] Generally, the rhamnolipid preparation (either "crude" or partially purified therefrom) is diluted to a final concentration of less than 70% rhamnolipid in the final rhamnolipid preparation, for example from about 5% to about 70% rhamnolipid.

[0132] In the present invention, the use of the term "rhamnolipid" refers without distinction to crude rhamnolipid or highly purified rhamnolipid, as well as to various mixtures of rhamnolipid components.

[0133] As mentioned above, rhamnolipids are secreted by Pseudomonas aeruginosa. Typically, Pseudomonas aeruginosa bacteria are cultured in a suitable medium and grown to a desired density. The bacteria themselves are removed from the medium by any method known in the art, such as centrifugation. The supernatant may be used directly as a crude preparation or may undergo further processing steps (e.g., concentration, filtration, column chromatography, etc.) well known to those skilled in the art. However, notably, the final rhamnolipid preparation is not highly purified and is referred to as "crude rhamnolipid," typically containing a mixture of both monorhamnolipids and dirhamnolipids, as well as other compounds. Those skilled in the art will understand the precise details of the culture, and partial purification methods can vary slightly and still fall within the scope of the present invention.

[0134] Preparation of crude and highly purified rhamnolipid preparations may be prepared by methods well known to those skilled in the art.

[0135] The compositions of the present invention may contain one or more types of rhamnolipids, which may be monorhamnolipids, dirhamnolipids, or a combination of the two.

[0136] Sophorolipid: Sophorolipids (also known as sophoroselipids or SLs) are a group of biosurfactants consisting of a dimeric sugar (sophorose) and a hydroxyl fatty acid linked by a β-glycosidic bond (Asmer et al., 1988).

[0137] According to Hu and Ju (2001) and Yanagisawa et al., U.S. Patent Application Publication No. 2011 / 0237531, there are two types of SLs: acidic (non-lactone) SLs and lactone SLs. The hydroxyl fatty acid moiety of acidic SLs has a free carboxylic acid functional group, while the hydroxyl fatty acid moiety of lactone SLs forms a macrocyclic lactone ring with the 4"-hydroxyl group of sophorose by intramolecular esterification. Sophorose lipids are a type of glycolipid biosurfactant and are generally classified into two forms: the lactone form, represented by the following structural formula (III): [ka] (wherein R1 and R2 each represent H or COCH3, R3 represents H or CH3, and when R3 is H, R4 represents a saturated or unsaturated C12-16 hydrocarbon group, and when R3 is CH3, R4 represents a saturated or unsaturated C11-15 hydrocarbon group), and an acid form represented by the following formula (IV): [ka] (wherein R1 to R4 are as defined above).

[0138] As is clear from the above, sophoroselipid has many derivatives characterized by the position and number of acetyl groups, the presence or absence of double bonds in the fatty acid side chain, the carbon chain length of the fatty acid side chain, the position of the glycosidic ether bond in the fatty acid side chain, the position of the hydroxyl group on the sophorose moiety (part of the lactone ring), and other structural parameters. Sophoroselipid generally occurs as a mixture of these compounds. Sophoroselipid is generally produced in the form of a highly viscous oil that is difficult to handle. However, the diacetyllactone form of sophoroselipid, which has a relatively high hydrophobicity, can be produced in a solid form.

[0139] The sophoroselipid biosurfactants of the present invention can be produced by culturing a microorganism capable of producing a glycolipid biosurfactant. Any microorganism capable of producing a glycolipid biosurfactant can be used to produce the sophoroselipid. According to U.S. Patent Application Publication No. 2011 / 0237531, sophoroselipid biosurfactants can be produced by yeasts of the genus Candida, such as Candida bombicola, Torulopsis, such as Torulopsis apicola, Wickerhamiella, and Starmerella. These can be produced by Torulopsis sp, Candida apicola, Candida lipolytica, Candida bogoriensis, or Torulopsis bombicola, according to Pattanathu, Production, Characterisation and Applications of Biosurfactants - Review, Biotechnology 7(2):360-370, 2008, ISSN 1682-296X (2008) Asian Network for Scientific Information.

[0140] Sophoroselipids can be produced by culturing the above-mentioned microorganisms in a medium. In the culture process of the present invention, generally, any medium may be used as long as it contains a nutrient source that can be assimilated by yeast cells.

[0141] Latex Monomer For purposes of this specification, the monomers from which the latex polymer can be derived are referred to as "latex monomers."

[0142] Preferably, these latex monomers include at least one acrylic monomer selected from the group consisting of acrylic acid, acrylic acid esters, methacrylic acid, and methacrylic acid esters. Additionally, other monomers for producing the latex polymer may optionally be selected from one or more monomers selected from the group consisting of styrene, α-methylstyrene, vinyl chloride, acrylonitrile, methacrylonitrile, ureido methacrylate, vinyl acetate, vinyl esters of branched tertiary monocarboxylic acids (e.g., vinyl esters sold under the trademark VEOVA by Shell Chemical Company or EXXAR neo vinyl esters by ExxonMobil Chemical Company), itaconic acid, crotonic acid, maleic acid, fumaric acid, and ethylene. C4-C8 conjugated dienes such as 1,3-butadiene, isoprene, and chloroprene may also be mentioned.

[0143] Preferably, the latex monomers include one or more monomers selected from the group consisting of n-butyl acrylate, methyl methacrylate, styrene, and 2-ethylhexyl acrylate. The latex polymer is typically selected from the group consisting of pure acrylic (containing acrylic acid, methacrylic acid, acrylic esters, and / or methacrylic esters as the primary monomers), styrene acrylic (containing styrene and acrylic acid, methacrylic acid, acrylic esters, and / or methacrylic esters as the primary monomers), vinyl acrylic (containing vinyl acetate and acrylic acid, methacrylic acid, acrylic esters, and / or methacrylic esters as the primary monomers), and acrylated ethylene vinyl acetate copolymer (containing ethylene, vinyl acetate, and acrylic acid, methacrylic acid, acrylic esters, and / or methacrylic esters as the primary monomers). As will be readily understood by those skilled in the art, the monomers can also include other primary monomers, such as acrylamide and acrylonitrile, as well as one or more functional monomers, such as itaconic acid and ureido methacrylate. In a particularly preferred embodiment, the latex polymer is pure acrylic, such as a butyl acrylate / methyl methacrylate copolymer derived from monomers including butyl acrylate and methyl methacrylate.

[0144] Additives to already formed aqueous latex dispersions In another embodiment, the biosurfactants described above can be used as additives to an aqueous dispersion of an already formed latex polymer, resulting in an aqueous composition comprising the biosurfactant compound and the latex polymer. Exemplary monomers from which the latex polymer may be formed are described above in the section entitled "Emulsion Polymerization."

[0145] For example, the present invention further includes a method for preparing a latex composition or latex polymer dispersion, comprising adding at least one biosurfactant (emulsifier) described above to an aqueous dispersion of a latex polymer to form a latex binder. When a biosurfactant compound is employed as an additive to an already formed aqueous latex dispersion, the resulting composition has a biosurfactant content of about 0.001 to 10, e.g., 0.01 to 2, or 0.1 to 0.6 parts per 100 parts by weight of the latex polymer dispersion or the total weight of the coating composition (based on the total composition, including water). Typically, the amount of biosurfactant added is less than 1% by weight of the composition (less than 10,000 ppm of the composition). For example, in one embodiment, the amount of biosurfactant added is 50 to 1000 ppm of the composition. The biosurfactant may be added entirely during blending or emulsification, or a portion may be added during emulsification and the remainder during blending to achieve the biosurfactant content of the resulting composition.

[0146] At least one pigment and other additives can then be mixed with the resulting latex binder in any suitable order to form an aqueous coating composition. The addition of a biosurfactant to the latex polymer results in a mixture having a low VOC content while maintaining a desirable level of mixture stability.

[0147] Additives in the formulation of paint or water-based coating compositions In another embodiment, the biosurfactants described above may be used as additives during the formulation of paint or aqueous coating compositions. Formulation is the stage in which additives are added to a base aqueous latex polymer dispersion to form a final product, such as a paint or coating. For example, pigments are typical additives added during the formulation of a paint from a raw aqueous latex polymer dispersion. When a biosurfactant compound is added during formulation into a paint or aqueous coating composition, such as an aqueous latex coating dispersion, the resulting composition has a biosurfactant content of about 0.001 to 10, e.g., 0.01 to 2, or 0.1 to 0.6 parts by weight per 100 parts by weight of the latex polymer dispersion or total weight of the coating composition (based on the total composition, including water). Typically, the amount of biosurfactant added is less than 1% by weight of the composition (less than 10,000 ppm of the composition). For example, in one embodiment, the amount of biosurfactant added is 50 to 1000 ppm of the composition. In one embodiment, the effective amount of biosurfactant is less than 1000 ppm, 800 ppm, 500 ppm, 300 ppm, 200 ppm, or 100 ppm of the composition. In another embodiment, the effective amount of biosurfactant is less than 100 ppm, or 90 ppm, or 80 ppm, or 70 ppm, or 60 ppm of the composition. In yet another embodiment, the effective amount of biosurfactant is between about 1 ppm and about 60 ppm of the composition. In a further embodiment, the effective amount of biosurfactant is between about 10 ppm and about 50 ppm of the composition. In another embodiment, the effective amount of biosurfactant is between about 20 ppm and about 50 ppm of the composition. In yet another embodiment, the effective amount of biosurfactant is between about 25 ppm and about 45 ppm of the composition.

[0148] The biosurfactant may be added entirely during blending, or a portion may be added during emulsification and the remainder during blending to achieve the amount of biosurfactant in the resulting composition.

[0149] The present invention further includes a method of preparing a paint or aqueous coating composition comprising adding the above-described biosurfactant during the formulation of a paint or aqueous coating composition containing at least one pigment and other additives to produce the final paint or aqueous coating composition.

[0150] Other additives As noted above, the aqueous coating compositions of the present invention include at least one latex polymer derived from at least one latex monomer, such as, for example, an acrylic monomer and / or other latex monomers described above.

[0151] The aqueous coating composition of the present invention comprises less than 2 wt. %, preferably less than 1.0 wt. %, of an antifreeze agent, based on the total weight of the aqueous coating composition. For example, the aqueous coating composition may be substantially free of antifreeze agents.

[0152] Aqueous coating compositions typically contain at least one pigment. As used herein, the term "pigment" includes non-film-forming solids such as pigments, extenders, and extenders. The at least one pigment is preferably selected from the group consisting of TiO (both anastase and rutile forms), clay (aluminum silicate), CaCO (both powder and precipitated forms), aluminum oxide, silicon dioxide, magnesium oxide, talc (magnesium silicate), barite (barium sulfate), zinc oxide, zinc sulfite, sodium oxide, potassium oxide, and mixtures thereof. Suitable mixtures include blends of metal oxides such as those sold under the trademarks MINEX (oxides of silicon, aluminum, sodium, and potassium available from Unimin Specialty Minerals), CELITES (aluminum oxide and silicon dioxide available from Celite Company), ATOMITES (available from English China Clay International), and ATTAGELS (available from Engelhard). More preferably, the at least one pigment comprises TiO2, CaCO3, or clay. Generally, the average particle size of the pigment ranges from about 0.01 to about 50 micrometers. For example, TiO2 particles used in the aqueous coating composition typically have an average particle size of about 0.15 to about 0.40 micrometers. The pigment may be added to the aqueous coating composition as a powder or in slurry form. The pigment is preferably present in the aqueous coating composition in an amount of about 5 to about 50% by weight, more preferably about 10 to about 40% by weight.

[0153] The coating composition may optionally contain additives such as one or more film-forming aids or coalescing agents. Suitable film-forming aids or coalescing agents include plasticizers and drying retarders, such as high-boiling polar solvents. Other conventional coating additives, such as dispersants, additional surfactants (i.e., wetting agents), rheology modifiers, antifoaming agents, thickeners, additional biocides, additional fungicides, colorants such as color pigments and dyes, waxes, fragrances, and cosolvents, may also be used in accordance with the present invention. For example, nonionic and / or ionic (e.g., anionic or cationic) surfactants may be used to form the polymer latex. These additives are typically present in the aqueous coating composition in an amount of 0 to about 15 wt %, more preferably about 1 to about 10 wt %, based on the total weight of the coating composition.

[0154] Aqueous coating compositions typically contain less than 10% antifreeze, based on the total weight of the aqueous coating composition. Exemplary antifreeze agents include ethylene glycol, diethylene glycol, propylene glycol, glycerol (1,2,3-trihydroxypropane), ethanol, methanol, 1-methoxy-2-propanol, 2-amino-2-methyl-1-propanol, and FTS-365 (a freeze-thaw stabilizer manufactured by Inovachem Specialty Chemicals). More preferably, the aqueous coating composition contains less than 5.0% or is substantially free (e.g., less than 0.1%) of antifreeze. Thus, the aqueous coating compositions of the present invention preferably have a VOC level of less than about 100 g / L, more preferably about 50 g / L or less.

[0155] The remainder of the aqueous coating composition of the present invention is water. While most of the water is present in the polymer latex dispersion and other components of the aqueous coating composition, water is generally also added separately from the aqueous coating composition. Typically, the aqueous coating composition contains about 10% to about 85% by weight of water, more preferably about 35% to about 80% by weight. In other words, the total solids content of the aqueous coating composition is typically about 15% to about 90%, more preferably about 20% to about 65%.

[0156] Coating compositions are typically formulated so that the dried coating contains at least 10% by volume dry polymer solids and an additional 5-90% by volume non-polymer solids in the form of pigments. The dried coating may also contain additives such as plasticizers, dispersants, surfactants, rheology modifiers, antifoaming agents, thickeners, additional biocides, additional fungicides, colorants, waxes, etc., that do not evaporate upon drying of the coating composition.

[0157] In one preferred embodiment of the present invention, the aqueous coating composition is a latex paint composition comprising at least one latex polymer derived from at least one acrylic monomer selected from the group consisting of acrylic acid, acrylic acid esters, methacrylic acid, and methacrylic acid esters, as well as at least one polymerizable alkoxylated surfactant, at least one pigment, and water. As noted above, the at least one latex polymer may be pure acrylic, styrene acrylic, vinyl acrylic, or acrylated ethylene vinyl acetate copolymer.

[0158] The present invention further includes a method for preparing an aqueous coating composition by mixing together at least one latex polymer derived from at least one monomer and copolymerized and / or blended with at least one biosurfactant described above, and at least one pigment. Preferably, the latex polymer is in the form of a latex polymer dispersion. The additives described above can be added to the latex polymer, pigment, or combination thereof in any suitable order to provide these additives in the aqueous coating composition. For paint formulations, the aqueous coating composition preferably has a pH of 7 to 10.

[0159] Most latex emulsions are water-based and susceptible to microbial attack. Biocides are typically added to the finished latex to protect it from microbial attack after all processing is complete. Biocides are substances that kill or inhibit the growth of microorganisms such as bacteria, fungi, and algae. These biocides may be selected from one or more members of the group consisting of chlorinated hydrocarbons, organometallics, halogen-releasing compounds, metal salts, quaternary ammonium compounds, phenols, and organosulfur compounds. An example of an organosulfur compound is an isothiazolinone (also known as isothiazolothione) structure-based compound.

[0160] An advantage of the present invention is that the use of biosurfactants can reduce the use of potentially less environmentally friendly biocidal chemicals (biocides). For example, the inventors have discovered that the combination of biosurfactants, such as monorhamnolipids, allows for the use of less isothiazolinone biocides in cans.

[0161] U.S. Patent No. 5,373,016 to Brown et al. discloses isothiazolinone biocides. The biocidal activity of these compounds is affected by the inactivation of essential enzymes in microbial metabolism that require sulfhydryl groups for activity. These enzymes include phosphoenolpyruvate transferase and many dehydrogenases. The thio moiety of the isothiazolinone or isothiazolothione compound reacts with the free sulfhydryl group of the enzyme, forming a disulfide bond between the enzyme molecule and the isothiazolinone or isothiazolothione molecule, making the sulfhydryl unavailable for interaction with substrates or effector molecules.

[0162] Biocides widely used as latex preservatives include PROXEL GXL, which has the active ingredient 1,2-benzisothiazolin-3-one (BIT), PROMEXAL W50, which has the active ingredient 2-methyl-4,5-trimethylene-4-isothiazolin-3-one, and KATHON LX, which is a blend of 5-chloro-2-methyl-4-isothiazolin-3-one and 2-methyl-4-isothiazolin-3-one active ingredients.

[0163] A typical isothiazolinone or isothiazolothione has the general formula (V): [ka] or a salt or complex thereof, wherein X is oxygen or sulfur; R is hydrogen, a substituted or unsubstituted hydrocarbyl group, a substituted or unsubstituted hydrocarbylthio group, a substituted or unsubstituted hydrocarbyloxy group, or a carbamoyl group; and A and D are each independently hydrogen, a halogen atom, a cyano group, a substituted or unsubstituted hydrocarbyl group, or a direct bond to the other of A or D.

[0164] When R, A, and D are or include substituted hydrocarbyl groups, the substituents are preferably independently halogen, alkoxy, or alkylthio, where the alkyl group contains 1 to 4 carbon atoms. When R is a carbamoyl group, it preferably has the general formula --CON(H)(R 1 ), wherein R 1 is a hydrogen atom or a hydrocarbyl group which may be substituted with halogen, alkoxy, or alkylthio substituents. Generally, it is preferred that R is a hydrogen atom or a lower alkyl group of 1 to 4 carbon atoms. Most preferably, R is a hydrogen or methyl group.

[0165] Preferably, A and D together with the carbon atoms to which they are attached form a 5- or 6-membered substituted or unsubstituted ring. The ring substituents are preferably halogen, alkyl of 1 to 4 carbon atoms, alkoxy of 1 to 4 carbon atoms, or alkylthio of 1 to 4 carbon atoms. The ring may contain heteroatoms, such as nitrogen atoms, replacing carbon atoms. Most preferably, A and D form a hydrocarbon ring, such as benzene, cyclopentene, or cyclohexene.

[0166] Alternatively, A and D are separate groups. Preferably, at least one of A and D is not a hydrogen atom, and most preferably, at least one of A and D is a halogen atom or an alkyl group of 1 to 4 carbon atoms.

[0167] Biocidal isothiazolinone compounds include 5-chloro-2-methyl-4-isothiazolin-3-one (wherein R is methyl, A is hydrogen, and D is chlorine), 2-methyl-4-isothiazolin-3-one (wherein R is methyl, A and D are both hydrogen), 4,5-dichloro-2-methylisothiazolin-3-one (wherein R is methyl, A and D are both chlorine), 2-n-octylisothiazolin-3-one (wherein R is n-octyl, A and D are both hydrogen), ), 1,2-benzisothiazolin-3-one (wherein R is hydrogen and A and D together with the carbon atoms to which they are attached form a benzene ring), 4,5-trimethylene-4-isothiazolin-3-one (wherein R is hydrogen and A and D together with the carbon atoms to which they are attached form a cyclopentene ring), and 2-methyl-4,5-trimethylene-4-isothiazolin-3-one (wherein R is methyl and A and D together with the carbon atoms to which they are attached form a cyclopentene ring).

[0168] Typical biocidal compounds of this family that can be used as additional biocidal compounds in the present invention are those in which R is hydrogen and A and D together form an unsubstituted 5- or 6-membered hydrocarbon ring, such as in the compounds 1,2-benzisothiazolin-3-one and 4,5-trimethylene-4-isothiazolin-3-one.

[0169] Certain isothiazolinone or isothiazolothione compounds that can be used as biocidal compounds can have improved water solubility when in the form of a salt or complex. The salt or complex can be with any suitable cation, such as an amine (including alkanolamine) or a metal. Preferably, any metal salt or complex contains a monovalent metal, such as an alkali metal. The alkali metal can be lithium, sodium, or potassium. Most preferably, the alkali metal salt is a sodium salt, given the availability of suitable sodium compounds from which to prepare the salt.

[0170] Certain isothiazolinone compounds useful as biocides decompose in the presence of alkali. Examples of alkali-sensitive compounds are 5-chloro-2-methyl-4-isothiazolin-3-one and 2-methyl-4-isothiazolin-3-one. Therefore, the pH of the alkali-sensitive composition of the present invention should be maintained at a value of about 8 or less.

[0171] If the biosurfactant is added after emulsification, it is typically added in an amount of 0.1 to 1000 ppm, preferably 0.1 to 500 ppm, more preferably 0.1 to 100 ppm, more typically 1 to 100 ppm, or 1 to 50 ppm of the total composition. The isothiazolinone may be present in an amount of 0.5 to 200 ppm, more typically 0.5 to 100 ppm, or 1 to 100 ppm, or 0.5 to 25 ppm of the total composition.

[0172] Typically, the weight ratio of biosurfactant to isothiazolinone is from 0.8:1 to 325:1, more typically from 20:1 to 35:1.

[0173] Particularly when treating bacteria, the aqueous coating composition further comprises an isothiazolinone biocide, typically in a weight ratio of biosurfactant to isothiazolinone biocide of 200-500:0.3-1.

[0174] When treating yeasts and fungi, the aqueous coating composition further comprises an isothiazolinone biocide, typically in a weight ratio of biosurfactant to isothiazolinone biocide of 200-500:5-30.

[0175] The invention will now be described in further detail by the following non-limiting examples. [Example]

[0176] In microbiology, the minimum inhibitory concentration (MIC) is defined as the lowest concentration of an antimicrobial agent that inhibits the growth of a microorganism after overnight or longer incubation. Minimum inhibitory concentrations are important in diagnostic laboratories to confirm microbial resistance to antimicrobial agents and also to monitor the activity of new antimicrobial agents. Lower MICs are generally required for acceptable performance and are therefore an indicator of a better antimicrobial agent. MIC determination is generally considered the basic or standard laboratory measurement of antimicrobial activity against an organism.

[0177] Testing Procedures and Protocols Biocides tested: Methylchloroisothiazolinone / Methylisothiazolinone (CMIT / MIT) (also known as KATHON): Benzisothiazolinone [BIT] Methylisothiazolinone [MIT]

[0178] 3-Chloromethylisothiazolinone has the formula A. [ka] Methylisothiazolinone has the formula B. [ka] BIT [benzisothiazolinone] has the formula C. [ka]

[0179] Microorganism used: Pseudomonas aeruginosa ATCC 9027 Tested biosurfactants: 1. R95D90 (Sigma-Aldrich) 95% pure rhamnolipid with 90% dirhamnolipid predominance 2. R95M90 (Sigma-Aldrich) 95% pure rhamnolipid with 90% monorhamnolipid predominance 3. Natural saponin

[0180] The MIC test is a method for determining the minimum inhibitory concentration of a compound required to inhibit or kill a test organism. The MIC50 test is a method for determining the minimum inhibitory concentration of a compound required to inhibit or kill 50% of the test organisms.

[0181] Detailed Steps 1. The method was based on MIC (minimum inhibitory concentration) determination by two-fold dilutions of standards prepared in appropriate media and tested in 96-well microtiter plates.

[0182] 2. A four-fold concentration of the active substance from the biosurfactant stock solution [400 ppm] was prepared and distributed into columns 4-6.

[0183] 3. The plate was divided into four compartments. Unless otherwise stated, columns 1-3 received a combination of biosurfactant and biocide, columns 4-6 received biocide only, and columns 7-9 received biosurfactant only. Column 10 was left empty, column 11 was blank medium, and column 12 was medium supplemented with a suspension of organisms.

[0184] 5. One microtiter plate was used per test organism and biocide. The dilution scheme is attached as a separate PDF file "Dilution Scheme".

[0185] 6. Aliquot 100 μL of sterile water into columns 4-6, 11, and 12 with the help of a 12-channel pipettor, and 50 μL into columns 1-3 and 7-9.

[0186] 7. 50 μL of an 8x stock solution of the appropriate biocide (MIT, BIT, or Kathon) was dispensed into columns 1-3 of row A.

[0187] 8. After mixing with the help of a multichannel pipettor, 50 μL from the wells in row A was transferred to the second row [B], and after mixing, 50 μL was transferred to row C, and this operation was repeated up to row G, discarding the 50 μL from row H (the last row).

[0188] 9. Make a 4x stock solution [400 ppm] of each of the biosurfactants. Distribute 50 µL of biosurfactant into four different 96-well plates in columns 7-9 on each of the corresponding plates.

[0189] 10. In wells 4-6, 100 μL of 4x concentration of each biocide was added to the top row A and then serially diluted down to row H, while the final 100 μL from row H was discarded.

[0190] 11. Columns 1-3 and 7-9 received 50 μL of 4x biosurfactant.

[0191] 12. In a separate tube, a bacterial inoculum was prepared from a 24-hour grown culture by suspending the cells in 2x tryptic soy broth medium for bacteria.

[0192] 13. The bacterial inoculum was adjusted to 5-6 log cfu / ml by measuring turbidity.

[0193] 14. With the aid of a multichannel pipettor, 100 μL aliquots of organisms were distributed into each well (except column 11, which received blank medium).

[0194] 15. Plates were incubated at 35°C for 24 hours for bacterial growth.

[0195] 16. Positive or negative growth in the wells was recorded visually. Viability was assessed by measuring absorbance at 660 nm and adding resazurin dye. Note: In the case of bacterial growth, positive and negative growth were determined by adding 10 μL of resazurin stock solution [250 mg / 50 mL] and determining the color change from blue to pink. The MIC is determined as the lowest concentration of biocide at which no growth is observed. Turbidity measurements were averaged for each concentration range to determine the MIC50 of each biocide with and without the test biosurfactant.

[0196] result: Commercially available monorhamnolipid at a 50 ppm activity level was effective in reducing the MIC50 values of all three tested biocides, including MIT, BIT, and Kathon.

[0197] As can be seen in Table 1 and Figures 1-3, the 95% research-grade monorhamnolipid-dominant biosurfactant (R95M90) alone at 50 ppm was also effective in reducing the MIC values of all three tested biocides, while the purified dirhamnolipid-dominant (R95D90) version was able to reduce the concentration of only the BIT biocide.

[0198] The adjuvant effect was restored by mixing purified di-monorhamnolipid and monorhamnolipid-predominant together in equal proportions (R95M90 + R95D90), suggesting that the adjuvant properties of rhamnolipid biosurfactants are primarily due to the activity of the monorhamnolipid homologues.

[0199] [Table 1]

[0200] All biosurfactants were tested at a final concentration of 50 ppm active. The term "BS" stands for "biosurfactant." Each data point is the MIC value (in ppm) tested against Pseudomonas aeruginosa. Only the monorhamnolipid component appears to be sufficient.

[0201] [Table 2]

[0202] [Table 3]

[0203] [Table 4]

[0204] In the above detailed description, preferred embodiments have been set forth in detail to enable the practice of the invention. While the invention has been described with reference to these specific preferred embodiments, it will be understood that the invention is not limited to these preferred embodiments. Rather, the invention encompasses numerous alternatives, modifications, and equivalents, as will become apparent in light of the following detailed description. It will be understood that, upon reading the above description of the invention, those skilled in the art will be able to make changes and variations therefrom. These changes and variations are intended to be included within the spirit and scope of the claims appended hereto.

[0205] The present invention includes the following embodiments. [1] An aqueous coating composition, (a) at least one latex polymer; (b) a biocide; and (c) a biosurfactant, the biosurfactant comprising a monorhamnolipid in an amount effective to reduce the required concentration of the biocide in the coating composition compared to a similar composition without the biosurfactant; (d) water; and an aqueous coating composition comprising a dispersion comprising: [2] The composition according to [1], further comprising dirhamnolipid, wherein the weight percent ratio of monorhamnolipid to dirhamnolipid is within the range of approximately 90:10 to 99:1, respectively. [3] The composition according to [1], further comprising dirhamnolipid, wherein the weight percent ratio of monorhamnolipid to dirhamnolipid is within the range of approximately 85:15 to 99.5:0.5, respectively. [4] The composition according to [1], further comprising dirhamnolipid, wherein the weight percent ratio of monorhamnolipid to dirhamnolipid is within the range of approximately 80:20 to 99.9:0.1, respectively. [5] The composition according to [1], further comprising dirhamnolipid, wherein the weight percent ratio of monorhamnolipid to dirhamnolipid is within the range of approximately 50:50 to 99.9:0.1, respectively. [6] The composition of [1], wherein the effective amount of the biosurfactant is less than 5000 ppm, 3000 ppm, 2000 ppm, 1000 ppm, 800 ppm, 500 ppm, 300 ppm, 200 ppm, or 100 ppm of the composition. [7] The composition of [1], wherein the effective amount of the biosurfactant is less than 60 ppm of the composition. [8] The composition according to [1], wherein the effective amount of the biosurfactant is from about 1 ppm to about 60 ppm of the composition. [9] The composition according to [1], wherein the effective amount of the biosurfactant is about 10 ppm to about 50 ppm of the composition.

[10] The composition according to [1], wherein the effective amount of the biosurfactant is about 20 ppm to about 50 ppm of the composition.

[11] The composition according to [1], wherein the effective amount of the biosurfactant is about 25 ppm to about 45 ppm of the composition.

[12] The composition of [1], wherein the at least one biocide comprises an isothiazolinone biocide.

[13] The composition of [1], further comprising at least one pigment, wherein the latex polymer comprises at least one acrylic monomer unit.

[14] The composition according to

[13] , wherein the latex polymer is further derived from one or more monomers selected from the group consisting of styrene, α-methylstyrene, vinyl chloride, acrylonitrile, methacrylonitrile, ureido methacrylate, vinyl acetate, vinyl esters of branched tertiary monocarboxylic acids, itaconic acid, crotonic acid, maleic acid, fumaric acid, ethylene, and C4-C8 conjugated dienes.

[15] A process for using biosurfactants for polymerization, comprising polymerizing a reaction mixture to prepare a latex polymer, the reaction mixture comprising at least one monomer and at least one biosurfactant comprising a monorhamnolipid.

[16] The process of

[15] , wherein polymerizing the emulsion comprises forming a stable aqueous pre-emulsion from the at least one monomer and the biosurfactant, and forming the reaction mixture comprising the pre-emulsion, an initiator, and water.

[17] The process of

[15] , wherein polymerizing the emulsion comprises forming an initiator solution comprising the initiator; forming a stable aqueous pre-emulsion comprising the at least one monomer and the biosurfactant; adding the initiator solution to a reactor; and adding the pre-emulsion to the reactor to form the reaction mixture.

[18] The process of

[15] , further comprising at least one pigment.

[19] The process of

[18] , wherein the at least one pigment comprises at least one pigment selected from the group consisting of TiO2, clay, CaCO3, aluminum oxide, silicon dioxide, magnesium oxide, talc (magnesium silicate), barite (barium sulfate), zinc oxide, zinc sulfite, sodium oxide, potassium oxide, and mixtures thereof.

[20] The process of

[15] , wherein the latex polymer is derived from at least one acrylic monomer selected from the group consisting of acrylic acid, acrylic acid esters, methacrylic acid, and methacrylic acid esters.

[21] The process of

[15] , wherein the monomer comprises at least one first monomer selected from the group consisting of acrylic acid, acrylic acid esters, methacrylic acid, methacrylic acid esters, styrene, vinyl toluene, vinyl acetate, vinyl esters of carboxylic acids higher than acetic acid, vinyl versatate, acrylonitrile, acrylamide, butadiene, ethylene, vinyl chloride, and mixtures thereof.

[22] The process of

[15] , wherein the at least one latex polymer is selected from the group consisting of pure acrylics, styrene acrylics, vinyl acrylics, acrylated ethylene vinyl acetate copolymers, and butyl acrylate / methyl methacrylate copolymers.

[23] - forming a stable aqueous pre-emulsion from the at least one first monomer, the at least one second monomer, and the biosurfactant; forming the reaction mixture comprising the pre-emulsion, an initiator, and water; said at least one first monomer is at least one acrylic monomer selected from the group consisting of acrylic acid, acrylic acid esters, methacrylic acid, and methacrylic acid esters;

[15] The process according to

[15] , wherein the at least one second monomer is selected from the group consisting of styrene, α-methylstyrene, vinyl chloride, acrylonitrile, methacrylonitrile, ureido methacrylate, vinyl acetate, vinyl esters of branched tertiary monocarboxylic acids, itaconic acid, crotonic acid, maleic acid, fumaric acid, ethylene, and C4-C8 conjugated dienes.

[24] The process of

[23] , wherein the initiator is selected from the group consisting of ammonium persulfate, hydrogen peroxide, sodium, potassium, ammonium peroxydisulfate, dibenzoyl peroxide, lauryl peroxide, di-tertiary butyl peroxide, 2,2'-azobisisobutyronitrile, t-butyl hydroperoxide, benzoyl peroxide, and mixtures thereof.

[25] The process according to

[23] , wherein the pre-emulsion is produced from 0.001 to 10 wt % of the biosurfactant based on the total weight of the aqueous pre-emulsion.

[26] The process of

[23] , wherein the aqueous coating composition comprises 0.5 to 10 parts by weight of a surfactant per 100 parts by weight of the monomers used to form the latex polymer, the surfactant being an emulsifier blend comprising (i) the biosurfactant and (ii) at least one nonionic surfactant or anionic surfactant, and the aqueous pre-emulsion comprises sufficient emulsifier blend to stabilize the aqueous pre-emulsion.

[27] The process of

[26] , wherein at least 5 wt.% of the emulsifier blend is the biosurfactant.

[28] The process of

[23] , further comprising adding an isothiazolinone and / or isothiazolothione biocide to the emulsion after polymerization.

[29] The emulsion is polymerized by a) forming a stable aqueous pre-emulsion from a monomer and the biosurfactant; b) forming the reaction mixture comprising the pre-emulsion, an initiator, and water; c) introducing the reaction mixture into a reactor and adding 1 to 10% by weight of the pre-emulsion to the reaction mixture; d) heating the reaction mixture obtained at the end of step c) to a temperature of 40°C to 90°C to produce seeds formed from the latex particles in the dispersion in water.

[30] A method for preparing an aqueous coating composition comprising contacting at least one aqueous dispersion of a latex polymer containing at least one biosurfactant with at least one biocide, wherein the biosurfactant comprises monorhamnolipid in an amount effective to reduce the concentration of the required biocide in the coating composition compared to a similar composition without the biosurfactant.

[31] The method of

[30] , wherein the at least one latex polymer comprises at least one member selected from the group consisting of pure acrylic, styrene acrylic, vinyl acrylic, and acrylated ethylene vinyl acetate copolymer.

[32] The method of

[30] , wherein the at least one latex polymer is derived from at least one monomer selected from the group consisting of acrylic acid, acrylic acid esters, methacrylic acid and methacrylic acid esters, styrene, vinyl toluene, vinyl acetate, vinyl esters of carboxylic acids higher than acetic acid, vinyl versatate, acrylonitrile, acrylamide, butadiene, ethylene, vinyl chloride, and mixtures thereof.

[33] The method of

[30] , further comprising adding at least one additive selected from the group consisting of dispersants, surfactants, rheology modifiers, antifoaming agents, thickeners, additional biocides, colorants, waxes, fragrances, and co-solvents to the mixture comprising the latex polymer and water.

[34] The method of

[30] , further comprising adding at least one pigment.

[35] The method of

[30] , wherein the effective amount of monorhamnolipid reduces the required biocide concentration in the coating composition by more than 20%, 30%, 40%, or 50% compared to a similar composition that does not contain the biosurfactant.

[36] The method of

[30] , wherein the effective amount of monorhamnolipid reduces the required concentration of biocide in the coating composition by more than 60%, or 70%, or 80% compared to a similar composition without the biosurfactant.

[37] The method according to

[30] , further comprising dirhamnolipid, wherein the weight percent ratio of monorhamnolipid to dirhamnolipid is within the range of about 90:10 to 99:1, respectively.

[38] The method according to

[30] , further comprising dirhamnolipid, wherein the weight percent ratio of monorhamnolipid to dirhamnolipid is within the range of about 85:15 to 99.5:0.5, respectively.

[39] The method according to

[30] , further comprising dirhamnolipid, wherein the weight percent ratio of monorhamnolipid to dirhamnolipid is within the range of approximately 80:20 to 99.9:0.1, respectively.

[40] The method according to

[30] , further comprising dirhamnolipid, wherein the weight percent ratio of monorhamnolipid to dirhamnolipid is within the range of approximately 50:50 to 99.9:0.1, respectively.

[41] The method of

[30] , wherein the effective amount of the biosurfactant is less than 5000 ppm, 2000 ppm, 1000 ppm, 800 ppm, 500 ppm, 300 ppm, 200 ppm, or 100 ppm of the composition.

[42] The method of

[30] , wherein the effective amount of the biosurfactant is less than 60 ppm of the composition.

[43] The method of

[30] , wherein the effective amount of the biosurfactant is from about 1 ppm to about 60 ppm of the composition.

[44] The method of

[30] , wherein the effective amount of the biosurfactant is about 10 ppm to about 50 ppm of the composition.

[45] The composition of [1], wherein the effective amount of monorhamnolipid reduces the required biocide concentration in the coating composition by more than 20%, 30%, 40%, or 50% compared to a similar composition that does not contain the biosurfactant.

[46] The composition of [1], wherein the effective amount of monorhamnolipid reduces the required biocide concentration in the coating composition by more than 60% compared to a similar composition without the biosurfactant.

Claims

1. 1. An aqueous coating composition comprising: The aqueous coating composition comprises (a) at least one latex polymer; (b) a biocide; and (c) a biosurfactant comprising a monorhamnolipid in an amount effective to reduce the required concentration of the biocide in the coating composition compared to a similar composition without the biosurfactant; (d) water; The biosurfactant further comprises a dirhamnolipid; the weight percent ratio of monorhamnolipid to dirhamnolipid is in the range of 80:20 to 99.9:0.1, respectively; An aqueous coating composition wherein the biocide comprises methylisothiazolinone, or benzisothiazolinone, or a mixture of methylchloroisothiazolinone and methylisothiazolinone.

2. 2. The composition of claim 1, wherein the weight percent ratio of monorhamnolipid to dirhamnolipid is in the range of 90:10 to 99:1, respectively.

3. 2. The composition of claim 1, wherein the weight percent ratio of monorhamnolipid to dirhamnolipid is in the range of 85:15 to 99.5:0.5, respectively.

4. 10. The composition of claim 1, wherein the effective amount of the biosurfactant is less than 5000 ppm, 3000 ppm, 2000 ppm, 1000 ppm, 800 ppm, 500 ppm, 300 ppm, 200 ppm, or 100 ppm of the composition.

5. 10. The composition of claim 1, wherein the effective amount of the biosurfactant is less than 60 ppm of the composition.

6. 10. The composition of claim 1, wherein the effective amount of the biosurfactant is from 1 ppm to 60 ppm of the composition.

7. 10. The composition of claim 1, wherein the effective amount of the biosurfactant is from 10 ppm to 50 ppm of the composition.

8. 10. The composition of claim 1, wherein the effective amount of the biosurfactant is from 20 ppm to 50 ppm of the composition.

9. 10. The composition of claim 1, wherein the effective amount of the biosurfactant is from 25 ppm to 45 ppm of the composition.

10. The composition of claim 1 further comprising at least one pigment, and wherein the latex polymer comprises at least one acrylic monomer unit.

11. The latex polymer may further comprise one or more of styrene, α-methylstyrene, vinyl chloride, acrylonitrile, methacrylonitrile, ureido methacrylate, vinyl acetate, vinyl esters of branched tertiary monocarboxylic acids, itaconic acid, crotonic acid, maleic acid, fumaric acid, ethylene, and C ４ ~C ８ 11. The composition of claim 10, derived from one or more monomers selected from the group consisting of conjugated dienes.

12. 1. A method for preparing an aqueous coating composition comprising contacting at least one aqueous dispersion of a latex polymer containing at least one biosurfactant with at least one biocide, wherein the biosurfactant comprises a monorhamnolipid in an amount effective to reduce the required concentration of the biocide in the coating composition compared to a similar composition without the biosurfactant, and the biosurfactant further comprises a dirhamnolipid, wherein the weight percent ratio of monorhamnolipid to dirhamnolipid is in the range of 80:20 to 99.9:0.1, respectively; The method wherein the biocide comprises methylisothiazolinone, or benzisothiazolinone, or a mixture of methylchloroisothiazolinone and methylisothiazolinone.

13. 13. The method of claim 12, wherein the at least one latex polymer comprises at least one member selected from the group consisting of pure acrylics, styrene acrylics, vinyl acrylics, and acrylated ethylene vinyl acetate copolymers.

14. 13. The method of claim 12, wherein the at least one latex polymer is derived from at least one monomer selected from the group consisting of acrylic acid, acrylic acid esters, methacrylic acid and methacrylic acid esters, styrene, vinyl toluene, vinyl acetate, vinyl esters of carboxylic acids higher than acetic acid, vinyl versatate, acrylonitrile, acrylamide, butadiene, ethylene, vinyl chloride, and mixtures thereof.

15. 13. The method of claim 12, further comprising adding at least one additive selected from the group consisting of dispersants, surfactants, rheology modifiers, antifoam agents, thickeners, additional biocides, colorants, waxes, fragrances, and co-solvents to the mixture comprising the latex polymer and water.

16. The method of claim 12 further comprising adding at least one pigment.

17. 13. The method of claim 12, wherein the effective amount of monorhamnolipid reduces the required concentration of biocide in the coating composition by more than 20%, 30%, 40%, or 50% compared to a similar composition without the biosurfactant.

18. 13. The method of claim 12, wherein the effective amount of monorhamnolipid reduces the required concentration of biocide in the coating composition by more than 60%, or 70%, or 80% compared to a similar composition without the biosurfactant.

19. 13. The method of claim 12, wherein the weight percent ratio of monorhamnolipid to dirhamnolipid is in the range of 90:10 to 99:1, respectively.

20. 13. The method of claim 12, wherein the weight percent ratio of monorhamnolipid to dirhamnolipid is in the range of 85:15 to 99.5:0.5, respectively.

21. 13. The method of claim 12, wherein the effective amount of the biosurfactant is less than 5000 ppm, 2000 ppm, 1000 ppm, 800 ppm, 500 ppm, 300 ppm, 200 ppm, or 100 ppm of the composition.

22. 13. The method of claim 12, wherein the effective amount of the biosurfactant is less than 60 ppm of the composition.

23. 13. The method of claim 12, wherein the effective amount of biosurfactant is from 1 ppm to 60 ppm of the composition.

24. 13. The method of claim 12, wherein the effective amount of the biosurfactant is from 10 ppm to 50 ppm of the composition.

25. 10. The composition of claim 1, wherein the effective amount of monorhamnolipid reduces the required biocide concentration in the coating composition by more than 20%, 30%, 40%, or 50% compared to a similar composition without the biosurfactant.

26. 10. The composition of claim 1, wherein the effective amount of monorhamnolipid reduces the required concentration of biocide in the coating composition by more than 60% compared to a similar composition without the biosurfactant.

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