HK1125095A - In-can and dry coating antimicrobial compositions having hydroxy analogs of methionine and derivatives - Google Patents

Description

Canned and dry-coated antimicrobial compositions containing hydroxy analogs and derivatives of methionine

Technical Field

The present invention relates to coating compositions including waterborne paints and alkyd-based paints, and more particularly, to coating compositions including antimicrobial agents. The antimicrobial agent is useful as a preservative for inhibiting a broad spectrum of microorganisms.

Background

Until the development of styrene-butadiene emulsions in the 40's of the 20 th century, high quality waterborne coatings were not obtained. With the increasing production of aqueous coatings, there is an urgent need to maintain the paint properties in the wet state. The presence of water and low molecular weight organic additives in aqueous paints (e.g., latex paints) creates an ideal environment for bacterial growth. In this humid state, fungi (such as molds and yeasts) can also grow in the lacquer, but bacteria of the genus pseudounicellular and enterobacter cause the most major damage. One of the most important causes of damage from bacteria is that under ideal conditions, bacteria grow much faster than fungi, to the extent that the bacteria double every 20 minutes.

On the other hand, the growth of microorganisms on dried paint films is influenced by a number of factors. These factors make it difficult to reasonably cost predict and prevent the growth of microorganisms. Some of the many variables that affect microbial growth on dry coatings or films are: climate, air quality, building design, substrate, greening, and paint formulation. Moulds (fungi) and algae have similar requirements for growth, but also some different requirements. Both molds and algae require moisture, oxygen, carbon and nitrogen fertilizers, trace minerals, and temperatures of 15-35 ℃ to sustain growth.

Mallow et al (U.S. patent No. 6,231,650) describe biocidal coating compositions, such as paints or coatings, that contain hydrated lime. The variety and concentration of the binder used in the composition is said to prolong the biocidal activity of hydrated lime by blocking the reaction of carbon dioxide with lime.

Garner et al (U.S. patent No. 5,366,004) describe paints containing pigments, liquids, binders, and metallic components that inhibit microbial growth. The metallic component comprises copper metal, copper carbonate, copper hydroxide, copper oxide, cuprous oxide, silver metal, silver oxide, zinc oxide, and zinc peroxide.

The toxicity of biocides currently used in commercially available coating compositions is a concern because these biocides enter the environment through contact with soil and water. In order to solve this problem, it is desirable to find a variety of environmentally safe and effective antimicrobial coating compositions.

Summary of The Invention

One aspect of the present invention provides a coating composition. The coating composition includes an antimicrobial agent and a binder. Typically, the antimicrobial agent is a hydroxy analog of methionine or a derivative of a hydroxy analog of methionine. In some embodiments, the hydroxy analog of methionine is a metal chelate comprising zinc ions or copper ions and at least one 2-hydroxy-4-methylthio-butanoic acid as a ligand source.

Another aspect of the present invention provides a method of inhibiting microbial growth and/or replication in a coating composition. The method includes adding an antimicrobial composition to the coating composition. Typically, the antimicrobial composition comprises a hydroxy analog of methionine and a binder.

Other aspects and features will be in part apparent and in part pointed out hereinafter.

Drawings

FIG. 1 illustrates the antimicrobial activity of BIOX-ASL. The aqueous paint formulation without BIOX-ASL (control) or three aqueous paint formulations with different concentrations of BIOX-ASL were contacted with 1.0% inoculum of pseudomonas aeruginosa (Psuedomonas aeruginosa) ATCC 10145 and Enterobacter aerogenes (Enterobacter aeogenenes) ATCC 13048 on day 0. Over the next 7 days, each paint formulation was sampled for the presence of bacteria. The number of bacterial colonies was scored from 0 (no bacterial recovery) to 4 (continuous offset of bacterial growth).

FIG. 2 illustrates the antimicrobial activity of BIOX-AWD. The aqueous paint formulation without BIOX-AWD (control) or three aqueous paint formulations with different concentrations of BIOX-AWD were contacted with 1.0% inoculum of Pseudomonas aeruginosa ATCC 10145 and Enterobacter aerogenes ATCC 13048 on day 0. Over the next 7 days, each paint formulation was sampled for the presence of bacteria. The number of bacterial colonies was scored from 0 (no bacterial recovery) to 4 (continuous offset of bacterial growth).

FIG. 3 illustrates the antimicrobial activity of BIOX-ASDA. An aqueous paint formulation without BIOX-ASDA (control) or two aqueous paint formulations with different concentrations of BIOX-ASDA were contacted with 1.0% inoculum of pseudomonas aeruginosa ATCC 10145 and enterobacter aerogenes ATCC 13048 on day 0. Over the next 7 days, each paint formulation was sampled for the presence of bacteria. The number of bacterial colonies was scored from 0 (no bacterial recovery) to 4 (continuous offset of bacterial growth).

FIG. 4 illustrates the antimicrobial activity of BIOX-C. An aqueous paint formulation without BIOX-C (control) or two aqueous paint formulations with different concentrations of BIOX-C were contacted with 1.0% inoculum of Pseudomonas aeruginosa ATCC 10145 and Enterobacter aerogenes ATCC 13048 on day 0. Over the next 7 days, each paint formulation was sampled for the presence of bacteria. The number of bacterial colonies was scored from 0 (no bacterial recovery) to 4 (continuous offset of bacterial growth).

Fig. 5 shows a bar graph of the Minimum Inhibitory Concentration (MIC) for various biocides. MICs using FD (N-methyl-2-hydroxymethyloxypropyl) -2' -hydroxypropylamine) and BIT (1, 2-benzisothiazoline) -3-one at concentrations of 40% and 100%, respectively, were from k. winkowski, "Optimizing the Use of biochides: blends of Actives "(ISP, 2004).

Detailed Description

It has been found that the hydroxy analog of methionine is an effective antimicrobial agent when added to a coating composition. Thus, these compounds or formulations containing these compounds may be included in coating compositions for inhibiting the growth and/or replication of microorganisms during storage of the compositions.

Generally, the coating or paint composition of the present invention comprises an antimicrobial agent and a binder, as will be described in more detail below. Optionally, the coating or coating composition may comprise additives in addition to the antimicrobial agent and the binder.

In addition, preferred coating compositions of the present invention have desirable mechanical properties such that when the composition dries to form a coating, the coating has a non-porous surface that is flexible and resistant to cracking, peeling or other deformation. Preferred compositions of the invention inhibit the growth and/or replication of microorganisms in the composition for a desired period of time.

In general, the coating compositions of the present invention may be oil-based, or they may be water-based. Adhesives suitable for use in aqueous compositions are generally more polar than adhesives suitable for use in oil-based compositions. Binders suitable for use in both oil-based and water-based coating compositions are described below.

A. Antimicrobial agents

In one exemplary embodiment, the antimicrobial agents of the present invention generally comprise at least one hydroxy analog of methionine. The term "hydroxy analog of methionine" as used herein broadly includes their own hydroxy analogs, their metal chelates or salts, their esters, amides and oligomers, and derivatives of hydroxy analogs of methionine as disclosed herein or as known in the art. The antimicrobial agent may optionally comprise other agents selected from the group consisting of: organic acids, inorganic acids, and combinations thereof. Various antimicrobial agents are described in more detail below.

1. Metal chelates or metal salts

The coating compositions and coatings of the present invention contain an antimicrobial agent. The antimicrobial agents of the present invention comprise a class of metal chelates and metal salts. In an exemplary embodiment, the metal chelate or metal salt is a hydroxy analog of methionine. For example, the metal chelate or metal salt may comprise a metal ion and a ligand, wherein the compound of formula 1 is the ligand source. The compounds of formula 1 have the following structure:

in the formula:

n is an integer of 0 to 2;

R¹is methyl or ethyl;

R²selected from hydroxyl and amino.

In various preferred embodiments of the invention, n is 2 and R is¹Is methyl, R²Is hydroxy (i.e. 2-hydroxy-4-methylthio-butanoic acid, commonly known as "HMTBA", under the trade name "HMTBA")Sold by Novus International, st.louis, Mo). Preferably, the metal ion is selected from the group consisting of: zinc ions, copper ions, manganese ions, iron ions, chromium ions, silver ions, cobalt ions, sodium ions, calcium ions, and combinations thereof. When the metal ions are copper, manganese, chromium, cobalt and iron, it is preferred that the metal ions are divalent, i.e. carry 2 positive charges. More preferably, the metal ion comprises zinc. In another preferred embodiment, the metal ions comprise copper.

In various preferred embodiments of the present invention, the compound of formula 1 comprises 2-hydroxy-4-methylthiobutanoic acid ("HMTBA"), i.e., n is 2, R¹Is methyl, R²Is a hydroxyl group. In a particularly preferred embodiment, the metal ion is copper, zinc or manganese. When the metal ion is copper or manganese, it is preferably divalent, i.e. carries 2 positive charges. In practice, the Zn cations are generally all divalent. In other metal chelates useful in the compositions and methods of the invention, it is also preferred that the metal ion is divalent. The ratio of ligand to metal ion in the chelate molecule is usually in the range of 1: 1 to 3: 1 or higher. Typically, the metal chelate may comprise a mixture of species in a ratio of 1: 1, 2: 1 and 3: 1. Preferably, chelateThe average ratio of ligand to metal ion in the compound molecule may generally be in the range of 1.5: 1 to 2.5: 1. The relative proportions of ligand and metal ion in aqueous media can be determined by the applicable stability constants. When n is equal to 2, R²Is amino, R¹In the case of methyl, i.e. the compound of formula 1 is methionine, a number of stability constants can be obtained from the literature. For n equal to 2, R²Is hydroxy, R¹Chelates that are methyl, i.e. where the compound of formula 1 is HMTBA, at least some stability constants can be obtained.

If the number of ligands is equal to the number of charges of the metal ion, the charges are generally balanced because the carboxyl portion of the ligand is in deprotonated form. Thus, in these chelates, each ligand corresponds to formula 1A:

in the formula R¹、R²And n is as defined above, i.e. in this case the chelate is also a dicarboxylate. For example, in a chelate where the metal cation carries 2 positive charges and the ratio of ligand to metal is 2: 1, each hydroxyl or amino group (R)²) Are understood to be linked to the metal by coordinate covalent bonds, whereas ionic bonds are widely present between the respective carboxylate and metal ions. A typical example is Zn²⁺、Cu²⁺、Mn²⁺A complex with two ions of 2-hydroxy-4-methylthiobutanoate. If the number of ligands exceeds the charge number of the metal ion, for example in a 3: 1 chelate of a divalent metal ion, the portion of the ligands exceeding the charge number will generally remain in a deprotonated state to balance the charge. On the other hand, if the positive charge of the metal ion exceeds the number of ligands, the charge can be balanced by the presence of other anions, such as chloride, bromide, iodide, bicarbonate, bisulfate, dihydrogen phosphate, and combinations thereof. Divalent anions may also be present.

Metal salts in which the metal has a positive charge of 1 or 2 may also be used. These salts are formed when a metal reacts with one or more ligands having the structure of formula 1 to form an ionic bond between the metal and the ligand. Typically, these metal salts can be prepared by contacting a source of metal ions with HMTBA. Preferably, a silver salt is used, wherein silver ions having a positive charge of 1 react with HMTBA to form the silver salt of 2-hydroxy-4-methylthiobutanoic acid. The silver metal salt may be prepared by contacting silver nitrate with HMTBA.

The metal chelates of the present invention can be generally prepared according to the methods described in U.S. Pat. Nos. 4,335,257 and 4,579,962. In a preferred method of preparation, a metal source compound such as a metal oxide, metal carbonate or metal hydroxide is added to a reaction vessel and an aqueous solution of HMTBA is added to the source compound. The concentration of HMTBA in the aqueous solution is preferably about 40 wt% to about 89 wt% or more. The reaction is usually carried out with moderate stirring for a period of more than 2 hours. Depending on the starting materials used, water and/or carbon dioxide are produced in the reaction. Typically, the reaction is carried out substantially at atmospheric pressure and the reactants are heated to a temperature in the range 90 ℃ to 130 ℃ to remove water.

After the reaction is substantially complete, the reactants continue to be heated in the reaction vessel until a substantially dry product is produced. Finally, the free water content was reduced to about 2% by weight and the product was converted to a free-flowing granular solid. The dried metal chelate product is optionally mixed with a calcium bentonite filler and ground to a powder.

Furthermore, HMTBA-Na salts can be prepared by reacting HMTBA with NaOH, which is a neutralization reaction of HMTBA acid with NaOH base. This neutralization reaction forms the HMTBA-Na salt and water.

When the carboxyl groups of the ligands are in deprotonated form, each ligand is believed to form a five-membered ring with the metal ion, and so the 2: 1 material has the following structure:

the concentration of the antimicrobial agent will vary depending upon factors such as the nature of the structure to which the coating composition is to be applied, the use of the structure, and other environmental conditions to which the structure is to be exposed. Generally, the concentration of the antimicrobial agent should be sufficient to reduce the rate of microbial growth and/or microbial replication as compared to the conditions caused by the presence of microorganisms in substantially the same paint composition except that the paint composition is free of metal chelates, metal salts, or other antimicrobial agents under the same conditions. Typically, the concentration of the metal chelate or metal salt in the coating composition is about 0.0005 wt.% to about 5 wt.%. Preferably, the concentration of the metal chelate or metal salt in the coating composition is from about 0.0005 wt.% to about 1 wt.%. More preferably, the concentration of the metal chelate or metal salt in the coating composition is from about 0.0005 wt.% to about 0.5 wt.%. In various embodiments, the concentration of the metal chelate or metal salt in the coating composition is about 0.001 wt.% to about 0.1 wt.%. In other embodiments, the concentration of the metal chelate or metal salt in the coating composition is about 0.1 wt.% to about 2 wt.%; more preferably from about 0.1 wt% to about 1 wt%. Typically, the concentration of metal chelate or metal salt in the coating is about 0.0006 wt% to 6.3 wt%; preferably about 0.0006 wt% to 1.3 wt%; more preferably from about 0.0006 wt% to about 0.6 wt%; more preferably from about 0.0013 to 0.13 weight percent. In other embodiments, the concentration of the metal chelate or metal salt in the coating is about 0.13 wt.% to about 2.5 wt.%; more preferably from about 0.13 wt% to about 1.3 wt%. However, the optimum concentration of metal chelate or metal salt in the coating composition or coating depends on the type of coating into which the metal chelate or metal salt is to be incorporated. For example, the metal chelate or metal salt must be present in greater or lesser amounts, depending on the other components of the coating composition and the tendency of the composition to provide an attractive medium for microbial growth and/or replication. Regardless of the rate of microbial growth and/or replication, however, the concentration of metal chelate or metal salt in the coating is preferably low enough so that the properties of the coating in terms of uniformity, thickness and continuity are not unduly affected. As discussed below, variables in the growth medium properties and coating properties of the coating composition may be considered as appropriate when determining the optimum concentration of metal chelate or metal salt in the coating composition of the present invention.

In various embodiments, the metal chelate or metal salt may be delivered into the coating composition or coating by adding a sodium salt of HMTBA (HMTBA-Na) and a metal salt (e.g., salts of zinc, copper, manganese, etc.) to the coating composition. In some cases, depending on the nature of the metal, HMTBA-Na will react with the metal salt to form an HMTBA-metal salt or chelate. For example, it is believed that the added HMTBA-Na and soluble zinc salts (e.g., zinc chloride, zinc nitrate, zinc carbonate, zinc sulfate, zinc acetate, zinc formate, zinc ammonium sulfate, zinc phosphate, zinc stearate, etc.) will react by ion exchange of sodium with zinc to form, after equilibration, HMTBA-Zn chelates and Na (anionic) salts.

In some cases, the particle size of the antimicrobial agent is important. For example, the commercially available copper 2-hydroxy-4-methylthiobutyrate chelate may have a particle size that is too large to achieve a smooth, uniform dispersion in the coating matrix. Generally, if the particle size of the chelate is considered too coarse for a particular application, it may be mechanically milled to a smaller particle size. To achieve a highly uniform dispersion that is stable over time and/or to provide a flat, uniform finish coating, it is desirable to reduce the average particle size of the metal chelate or metal salt to less than about 10 microns, more preferably to about 0.2 to 5 microns, for example about 2 microns, with at least about 95% by weight of the particles being in the average particle size range of about 0.05 to 8 microns.

One or more metal chelates or metal salts and one or more components selected from the group consisting of: a compound of formula 2, an organic acid, an inorganic acid, other biocide, and combinations thereof.

2. Hydroxy analogs of methionine of formula 2

Another class of agents effective for inhibiting the growth and/or replication of microorganisms in a coating or coating composition of the present invention are hydroxy analogs of methionine or their derivatives, including compounds of formula 2 and salts, esters, or amides thereof:

in the formula:

R³is methyl or ethyl; and

m is an integer of 0 to 2.

In preferred embodiments, m is 2 and R³Is methyl (i.e. 2-hydroxy-4-methylsulfanyl-butyric acid). The 88 wt% HMTBA product is available from Nowa Silk International Inc. One or more compounds of formula 2 may be present in the coating or coating composition together with one or more components selected from the group consisting of: metal chelates or metal salts, organic acids, inorganic acids, and combinations thereof.

In the coating composition, the total concentration of the one or more compounds of formula 2 is about 0.0005 wt.% to about 5 wt.%; preferably from about 0.0005 wt.% to about 1 wt.%; more preferably from about 0.0005 wt% to about 0.5 wt%. In other embodiments, the concentration of the one or more compounds of formula 2 in the coating composition is from about 0.1 wt% to about 2 wt%; more preferably from about 0.1 wt% to about 1 wt%. The total concentration of the one or more compounds of formula 2 in the coating is about 0.0006 wt% to about 6 wt%; preferably about 0.0006 wt% to 1.3 wt%; more preferably from about 0.0006 wt% to about 0.6 wt%. In other embodiments, the concentration of the one or more compounds of formula 2 in the coating is about 0.13 wt% to about 2.5 wt%; more preferably from about 0.13 wt% to about 1.3 wt%. One or more compounds of formula 2 may be present in the coating or coating composition together with one or more components selected from the group consisting of: metal chelates or metal salts, organic acids, inorganic acids, other biocides, and combinations thereof.

3. Organic acids

Another class of agents effective in inhibiting the growth and/or replication of microorganisms in the coating compositions of the present invention are organic acids. Organic acids are of the general formula RC (O) OH, wherein R is a hydrocarbyl or substituted hydrocarbyl group. The coating composition may contain one or more organic acid compounds. Preferably, the organic acid included in the coating composition has a pKa value of less than about 5.5.

In various embodiments of the invention, the organic acid is selected from the group consisting of: formic acid, acetic acid, propionic acid, butyric acid, benzoic acid, lactic acid, malic acid, tartaric acid, mandelic acid, citric acid, fumaric acid, sorbic acid, boric acid, succinic acid, adipic acid, glycolic acid, glutaric acid, and combinations thereof. Preferably, the organic acid is selected from the group consisting of: formic acid, lactic acid, benzoic acid, propionic acid, and combinations thereof.

The total concentration of other organic acids in the coating composition is from about 0.0005 wt.% to about 5 wt.%; preferably from about 0.0005 wt.% to about 1 wt.%; more preferably from about 0.0005 wt% to about 0.5 wt%. In other embodiments, the concentration of the other organic acid in the coating composition is about 0.1 wt% to about 2 wt%; more preferably from about 0.1 wt% to about 1 wt%. The total concentration of organic acids in the coating is about 0.0006 wt% to 6 wt%; preferably about 0.0006 wt% to 1.3 wt%; more preferably from about 0.0006 wt% to about 0.6 wt%. In other embodiments, the concentration of the other organic acid in the coating may be about 0.13 wt% to 2.5 wt%; more preferably from about 0.13 wt% to about 1.3 wt%. The organic acid may be mixed prior to being added to the coating composition at the concentrations described above. Such combinations of organic acids may contain about 50 to 90 weight percent formic acid prior to addition to the coating composition; preferably about 60 to 85 weight percent formic acid; more preferably from about 65 to 80 weight percent formic acid. Other combinations may contain about 10 to 30 weight percent lactic acid prior to addition to the coating composition; preferably about 15 to 25 weight percent lactic acid. Other combinations may contain 20 to 60 weight percent propionic acid prior to addition to the coating composition; preferably from about 25 to about 40 weight percent propionic acid; more preferably from about 30 to about 40 weight percent propionic acid.

In combinations where other organic acids are used, the combination contains about 50 to 90 weight percent fumaric acid prior to addition to the coating composition; preferably about 60 to 80% by weight fumaric acid; more preferably about 65 to 75 weight percent fumaric acid. In other combinations, the organic acid combination may contain about 10 to 50 weight percent benzoic acid prior to addition to the coating composition; preferably about 20 to 40 weight percent benzoic acid; more preferably from about 30 to 40% by weight benzoic acid.

One or more organic acids may be present in the coating composition with one or more components selected from the group consisting of: metal chelates or metal salts, compounds of formula 2, mineral acids, other biocides, and combinations thereof.

4. Inorganic acid

Another class of agents effective in inhibiting the growth and/or replication of microorganisms in the coating compositions of the present invention are mineral acids. One or more inorganic acid compounds may be included in the coating composition. The inorganic acid is selected from the group consisting of: phosphoric acid, sulfuric acid, phosphorous acid, hydrochloric acid, hydrobromic acid, nitric acid, and combinations thereof. Preferably, the mineral acid is selected from the group consisting of: phosphoric acid, sulfuric acid, nitric acid, hydrochloric acid, and combinations thereof. In a preferred embodiment, the inorganic acid comprises phosphoric acid.

The total concentration of inorganic acid in the coating composition is from about 0.0005 wt.% to about 0.5 wt.%; preferably from about 0.0005 wt.% to about 0.25 wt.%; more preferably from about 0.0005 wt.% to about 0.1 wt.%. In other embodiments, the total concentration of inorganic acid in the coating composition is from about 0.1 wt% to about 2 wt%; more preferably from about 0.1 wt% to about 1 wt%. The total concentration of inorganic acid in the coating is about 0.0006 wt% to 0.6 wt%; preferably about 0.0006 wt% to about 0.3 wt%; more preferably from about 0.0006 wt% to about 0.13 wt%. In other embodiments, the total concentration of inorganic acid in the coating is about 0.13 wt% to about 2.5 wt%; more preferably from about 0.13 wt% to about 1.3 wt%. One or more mineral acids may be present in the coating composition together with one or more components selected from the group consisting of: metal chelates or metal salts, compounds of formula 2, organic acids, other biocides, and combinations thereof.

Various combinations of the above antimicrobial agents include, for example, a compound of formula 2, an organic acid, and optionally an inorganic acid. The following concentrations are based on the amounts present in the combination prior to addition to the coating composition. These combinations may comprise about 10 to 70 weight percent HMTBA; preferably about 25 to 50 weight percent HMTBA; more preferably from about 30 to 40 weight percent HMTBA. Other combinations may include about 20 to 60 weight percent formic acid; preferably about 30 to 55 weight percent formic acid; more preferably about 40 to 50 weight percent formic acid. Other combinations may include about 5 to 20 weight percent lactic acid; preferably about 5 to 15% by weight of lactic acid. Other combinations may comprise about 5 to 40 weight percent propionic acid; preferably about 10 to 30 weight percent propionic acid; more preferably from about 15 to 25 weight percent propionic acid.

In combinations using other organic acids, the combination may include about 20 to 60 weight percent fumaric acid; preferably about 30 to 50 weight% fumaric acid; more preferably about 35 to 45 weight percent fumaric acid. In other combinations, the organic acid combination can comprise about 5% to 40% by weight benzoic acid; preferably about 10 to 30% by weight benzoic acid; more preferably from about 15 to 25 weight percent benzoic acid.

Various preferred combinations comprise about 30 to 40 wt.% HMTBA and about 40 to 50 wt.% formic acid. Other combinations include about 30 to 40 wt.% HMTBA, about 40 to 50 wt.% formic acid, and about 5 to 15 wt.% lactic acid. While other combinations comprise about 30 to 40 wt.% HMTBA, about 40 to 50 wt.% formic acid, about 5 to 15 wt.% lactic acid, and about 5 to 15 wt.% phosphoric acid.

Other preferred combinations comprise about 30 to 40 wt.% HMTBA, about 40 to 50 wt.% formic acid and about 15 to 25 wt.% propionic acid.

Other combinations include about 30 to 40 weight percent calcium bis (2-hydroxy-4-methylthiobutyrate) and about 35 to 45 weight percent fumaric acid. Preferably, these combinations comprise from about 30 to 40 weight percent calcium bis (2-hydroxy-4-methylthiobutanoate), from about 35 to 45 weight percent fumaric acid, and from about 15 to 25 weight percent benzoic acid.

In various preferred embodiments, the antimicrobial agent is selected from the group consisting of: HMTBA-Zn, HMTBA-Cu, BIOX-ASL, BIOX-ASDA, BIOX-AWD, and combinations thereof. HMTBA-Zn is the zinc chelate of HMTBA, HMTBA-Cu is the copper chelate of HMTBA, and BIOX-ASL contains 35 wt% of 2-hydroxy-4-methylthiobutyric acid (88%), 45 wt% of formic acid, 10 wt% of phosphoric acid and 10 wt% of lactic acid; BIOX-AWD contained 40% by weight of 2-hydroxy-4-methylthiobutyric acid, 40% by weight of formic acid and 20% by weight of propionic acid; BIOX-ASDA contained 36.4% by weight of calcium bis (2-hydroxy-4-methylthiobutanoate), 41.9% by weight of fumaric acid, 20% by weight of benzoic acid, 0.9% by weight of flow assistants and 0.73% by weight of further additives.

5. Other biocides

Biocides ("secondary biocides") having a composition different from the biocides described above for paint preservation ("primary biocides") may optionally be included in the coating compositions of the present invention. Generally, these auxiliary biocides can inhibit the growth and/or replication of microorganisms in the coating compositions and/or coatings of the present invention. In some cases, the secondary biocide is particularly useful for inhibiting the growth and/or replication of microorganisms in the coating composition prior to application, while another group of secondary biocides is particularly useful for inhibiting the growth and/or replication of microorganisms in the dried coating.

The advantage of the combination of primary and secondary biocides is that the following combination of features is effectively maintained: inhibiting microbial growth and/or microbial replication while reducing the toxicity of the combination by reducing the amount of supplemental biocide necessary to inhibit such microbial growth and/or replication. Generally, the primary antimicrobial agents described above are less toxic to the environment after leaching out of the paint than other biocides contemplated herein.

In preferred embodiments, the primary antimicrobial agent of the present invention is incorporated into the coating composition along with various secondary biocides. These ancillary biocides are useful for inhibiting the growth and/or replication of microorganisms in coating compositions, can be, for example, formaldehyde-releasing agents (e.g., hexahydro-1, 3, 5-tris (2-hydroxyethyl) -s-triazine, oxazolidines (e.g., 4-dimethyl-1, 3-oxazolidine), quaternized salts of Hexamethylenetetramine (HTA) (e.g., 1- (3-chloroallyl) -3, 5, 7-triaza-1-azoniaadamantane chloride and methyl-3, 5, 7-triaza-1-azoniaadamantane chloride), bronopol (e.g., 2-bromo-2-nitropropane-1, 3-diol), 1, 2-dibromo-2, 4-dicyanobutane (DBDCB), and combinations thereof.

Preferred combinations of primary biocide and secondary biocide in the coating composition are (1) HMTBA-Zn, HMTBA-Cu, BIOX-ASL, BIOX-ASDA and/or BIOX-AWD with formaldehyde releasing agents such as triazines (e.g., hexahydro-1, 3, 5-tris (2-hydroxyethyl) -s-triazine); (2) HMTBA-Zn, HMTBA-Cu, BIOX-ASL, BIOX-ASDA and/or BIOX-AWD with oxazolidines such as 4, 4-dimethyl-1, 3-oxazolidine; (3) quaternized salts of HMTBA-Zn, HMTBA-Cu, BIOX-ASL, BIOX-ASDA and/or BIOX-AWD with Hexamethylenetetramine (HTA) such as 1- (3-chloroallyl) -3, 5, 7-triaza-1-azoniaadamantane chloride and methyl-3, 5, 7-triaza-1-azoniaadamantane chloride); (4) HMTBA-Zn, HMTBA-Cu, BIOX-ASL, BIOX BIOX-ASDA and/or BIOX-AWD with bronopol (i.e. 2-bromo-2-nitropropane-1, 3-diol); and (5) HMTBA-Zn, HMTBA-Cu, BIOX-ASL, BIOX-ASDA and/or BIOX-AWD with 1, 2-dibromo-2, 4-dicyanobutane (DBDCB).

In particular combinations, the total concentration of the combination of one or more primary biocides and the secondary biocide in the coating composition is from about 0.0005 wt.% to about 5 wt.%; preferably from about 0.0005 wt.% to about 1 wt.%; more preferably from about 0.0005 wt.% to about 0.5 wt.%; more preferably from about 0.001 wt% to about 0.5 wt%. In other embodiments, the total concentration of the one or more primary biocides combined with the secondary biocide in the coating composition is from about 0.1 wt.% to about 2 wt.%; preferably about 0.1 wt% to about 1 wt%. In the above combination, the total concentration of the one or more primary antimicrobial agents in combination with the secondary biocide in the coating is from about 0.0006 wt% to 6.3 wt%; preferably about 0.0006 wt% to 1.3 wt%; more preferably from about 0.0006 wt% to about 0.6 wt%; more preferably from about 0.0013 to 0.6 weight percent. In other embodiments, the total concentration of the one or more primary antimicrobial agents in combination with the secondary biocide in the coating is from about 0.13% to 2.5% by weight; preferably about 0.13 wt% to about 1.3 wt%.

In preferred embodiments, the primary antimicrobial agent of the present invention is incorporated into the coating along with various secondary biocides suitable for inhibiting the growth and/or replication of microorganisms in and/or on the dry coating. These other biocides may be, for example, 3-iodo-2-propynylbutyl carbamate, carbendazim (e.g., methyl N-benzimidazolyl-2-carbamate (BCM)), chlorothalonil (i.e., 2, 4,5, 6-tetrachloroisophthalonitrile), folpet (i.e., trichloromethylthiophthalimide), methyl and chloromethyl isothiazolines (isothiazoliones), 2-N-octyl-4-isothiazolin-3-One (OIT), dichloro-2-N-octyl-4-isothiazolin-3-one (DCOIT), azoles (e.g., tebuconazole), propiconazole (propiconazole) and thiabendazole), di-iodomethyl (iodomethyl) -p-tolylsulfone, and combinations thereof.

Preferred combinations of primary and secondary biocides in the coating are (1) HMTBA-Zn, HMTBA-Cu, BIOX-ASL, BIOX-ASDA and/or BIOX-AWD with 3-iodo-2-propynyl butylcarbamate; (2) HMTBA-Zn, HMTBA-Cu, BIOX-ASL, BIOX-ASDA and/or BIOX-AWD with carbendazim (e.g. methyl N-benzimidazolyl-2-carbamate (BCM)); (3) HMTBA-Zn, HMTBA-Cu, BIOX-ASL, BIOX-ASDA and/or BIOX-AWD with chlorothalonil (i.e. 2, 4,5, 6-tetrachloroisophthalonitrile); (4) HMTBA-Zn, HMTBA-Cu, BIOX-ASL, BIOX BIOX-ASDA and/or BIOX-AWD with folpet (i.e. trichloromethylthiophthalimide); (5) HMTBA-Zn, HMTBA-Cu, BIOX-ASL, BIOX BIOX-ASDA and/or BIOX-AWD with methyl and chloromethylisothiazoline; (6) HMTBA-Zn, HMTBA-Cu, BIOX-ASL, BIOX BIOX-ASDA and/or BIOX-AWD with 2-n-octyl-4-isothiazolin-3-One (OIT); (7) HMTBA-Zn, HMTBA-Cu, BIOX-ASL, BIOX BIOX-ASDA and/or BIOX-AWD with azoles (e.g. tebuconazole, propiconazole and thiabendazole); and (8) HMTBA-Zn, HMTBA-Cu, BIOX-ASL, BIOX-ASDA and/or BIOX-AWD with di-iodomethyl-p-tolylsulfone.

Of these combinations in the coating, the total concentration of the one or more primary antimicrobial agents combined with the secondary biocide is about 0.0006 wt% to 6.3 wt%; preferably about 0.0006 wt% to 1.3 wt%; more preferably from about 0.0006 wt% to about 0.6 wt%; more preferably from about 0.0013 to 0.6 weight percent. In other embodiments, the total concentration of the one or more primary antimicrobial agents in combination with the secondary biocide in the coating is from about 0.13% to 2.5% by weight; preferably about 0.13 wt% to about 1.3 wt%.

For the combination of the primary biocide and the secondary biocide described above in the coating composition and coating, the ratio of biocide to other biocide is about 1: 100 to 100: 1; preferably about 1: 10 to 10: 1; more preferably from about 1: 5 to about 5: 1; more preferably from about 1: 2 to about 2: 1. Thus, the terms "primary" and "secondary" are used herein only to distinguish between different types of antimicrobial agents and do not mean that the level of "primary" antimicrobial agent must be, or preferably is, higher than the concentration of "secondary" biocide.

In certain coating compositions, metal chelates may be used to stabilize one or more other biocides contained in the composition. Such stabilization of the metal chelate may be performed, for example, by reducing inactivation of 2-methyl-4-isothiazolin-3-one (MIT), 5-chloro-2-methyl-4-isothiazolin-3-one (CIT), 1, 2-benzisothiazol-3-one (BIT), and combinations thereof due to the action of amines, sulfides, sulfites, thiols, oxidizing agents, reducing agents, and combinations thereof. In order to reduce this deactivation and to maintain the high activity of MIT, CIT and BIT as biocides in coating compositions, it is believed to be advantageous to add metal chelates, in particular HMTBA-Cu. In this particular application, the HMTBA-Cu is added to the composition at a concentration of about 0.001 wt% to about 1 wt%; preferably about 0.01 wt% to 1 wt%; more preferably from about 0.1 wt% to about 1 wt%.

B. Adhesive agent

The coating composition of the present invention comprises an antimicrobial agent and a binder. The binder is a film-forming ingredient that binds the particles in the coating composition together. Here, the binder may be a drying oil, a resin, or an inorganic binder. Typically, different binders are used for oil-based coating compositions and water-based coating compositions. For oil-based coating compositions, the binder is soluble, miscible or dispersible in organic solvents. For example, as will be described in more detail below, the binder used in oil-based compositions is typically a drying oil or an alkyd resin. In water-based coating compositions, the binder is soluble or miscible in aqueous solvents or is emulsifiable or dispersible in aqueous solvents. For example, as will be described in more detail below, the binder used in water-based coating compositions is typically a vinyl or acrylic resin.

Drying oils may be included in the oil-based coating composition as binders. Typically, drying oils comprise glycerides of fatty acids with varying degrees of unsaturation. Saturated glycerides may also be present. They are called drying oils because they are capable of absorbing atmospheric oxygen, reacting with unsaturated glycerides to form oxidized functional groups, which further react to crosslink the fatty acid chains to form hard, flexible films. Typically the drying oil is selected from the group consisting of: linseed oil, walnut oil, poppy seed oil, ricinine oil (ricinene oil), soybean oil, castor oil, and combinations thereof.

The resins can be used in both oil-based and water-based coating compositions. The resin may be a natural resin or a synthetic resin, and may comprise a solid or semi-solid viscous substance obtained as a secretion from certain plants or prepared by simple molecular polymerization.

In addition to drying oils, oil-based coating compositions also typically comprise alkyd resins as binders. Although alkyd resins are useful in both oil-based and water-based coating compositions, they are generally more widely used in oil-based coating compositions. Alkyd resins are condensation products of polyols (e.g. glycerol, pentaerythritol), polybasic acids or anhydrides (e.g. phthalic anhydride) and oils or monobasic fatty acids.

Acrylic and vinyl resins are the most widely used resins in water-based coating compositions. Some water-based coating compositions are latex compositions that are water-thinnable paints where the binder comprises polyvinyl acetate (PVA), styrene-butadiene or acrylic resins. In preferred embodiments, the adhesive comprises an acrylic resin.

The concentration of acrylic, vinyl, PVA, and styrene-butadiene resins in the coating composition is about 10 wt% to about 30 wt%; preferably from about 10 wt% to about 20 wt%; more preferably from about 11 wt% to about 17 wt%. The concentration of acrylic, vinyl, PVA, and styrene-butadiene resins in the coating is about 13 wt% to 38 wt%; preferably about 13 wt% to about 25 wt%; more preferably from about 14 wt% to about 21 wt%.

In addition, inorganic binders may be used in the coating composition of the present invention. Suitable inorganic binders include calcium hydroxide (in the form of lime), hydrated lime, white cement, potassium silicates (e.g., potash water glass), and mixtures of alkali metal silicates with polymer dispersions (e.g., styrene-acrylate copolymers).

C. Additive agent

In various embodiments, the coating composition further comprises an additive. The additive may be selected from the group consisting of: diluents, pigments, fillers, biocides, and combinations thereof. The diluent for the oil-based coating composition is selected from the group consisting of: alcohols, aliphatic hydrocarbons, cycloaliphatic hydrocarbons, aromatic hydrocarbons, ketones, ether alcohols, esters, chlorinated hydrocarbons, and combinations thereof. In general, the diluent may act as a solvent for the antimicrobial agent and/or a binder for the composition. Preferably, the diluent for the oil-based coating composition is selected from the group consisting of methanol, ethanol, propanol, isopropanol, butanol, isobutanol, benzyl alcohol, mineral spirits, cyclohexane, toluene, xylene, methyl ethyl ketone, acetone, methyl isobutyl ketone, methyl isoamyl ketone, diacetone alcohol, cyclohexanone, 2-butoxyethanol, propylene glycol monomethyl ether, butyl diglycol, methoxypropyl acetate, n-butyl acetate, 2-ethoxyethyl acetate, dichloromethane, tetrachloroethane, trichloroethylene, and combinations thereof.

For water-based coating compositions, the diluent comprises water or a mixture of water and other water-miscible solvents or solvent mixtures, such as methanol, ethanol, propanol, and the like.

Preferably, the concentration of the diluent in the coating composition is from about 10 wt% to about 35 wt%; preferably about 15 wt% to about 25 wt%; more preferably from about 18 to about 22 weight percent.

In the coating of the present invention, typically, the diluent is volatilized after the coating composition is applied to the substrate. Thus, the dried and/or cured coating has the lowest diluent concentration.

Typically, pigments may be included in the coating compositions and coatings. The pigment may be an organic or inorganic pigment. Pigments commonly used in coatings are selected from the group consisting of phthalocyanine blue, hansa yellow, ochre, umber, quinacridone red, pigment red, phthalocyanine blue, phthalocyanine green, perylene red, carbon black, rutile and anatase titanium dioxide, lithopone, zinc sulfide, lead titanate, antimony oxide, zirconium oxide, barium sulfide, white lead, zinc oxide, white lead, red iron oxide, brown oxide, aluminum powder, vapor deposited aluminum powder, aluminum oxide powder, nickel powder, copper powder, brass powder, chromium powder, pearl-lustre mica powder, and pearl-lustre colored pearl mica powder, and combinations thereof.

The concentration of pigment in the coating composition is about 5 wt% to about 25 wt%; preferably from about 10 wt% to about 20 wt%; more preferably from about 12 wt% to about 17 wt%. Typically, the concentration of pigment in the coating is about 6 wt% to 31 wt%; preferably about 13 wt% to about 25 wt%; more preferably from about 15 wt% to about 21 wt%.

Fillers are materials which are generally of fine particle size, dispersible in organic and/or aqueous media and do not settle immediately after dispersion. Exemplary fillers are selected from calcium carbonate, iron oxide, kaolin, clay, titanium dioxide, alumina trihydrate, pyrophyllite, quartz, silica, fumed silica, precipitated silica, silicates, barium sulfate, antimony oxide, mica, calcium sulfate, magnesium hydroxide, feldspar, nepheline syenite, carbon black fillers, titanates, talc, gypsum, silica, wollastonite, bagasse, coconut shells/fibers, cork, grains, cotton-based materials (cotton-based), filsonite, nut shell flour (nutshell flours), rice hulls, sisal/hemp, soy, starch wood flour, and combinations thereof.

The concentration of filler in the coating composition is about 25 wt% to 50 wt%; preferably about 30 wt% to 45 wt%; more preferably from about 35 wt% to about 45 wt%. Typically, the concentration of filler in the coating is about 31 wt% to 63 wt%; preferably about 37 wt% to about 56 wt%; more preferably from about 44 wt% to about 56 wt%.

In addition, the coating compositions of the present invention may optionally contain extenders, thickeners, thixotropic agents, suspending agents, defoamers, antifoams, water softeners, and other functional components known to those skilled in the art.

D. Lacquer formulation

The coating compositions of the present invention can be formulated in a variety of ways. An exemplary water-based paint formulation is as follows.

Acrylic paint Silicone additive paint Silicone paint

Weight of the components

Water 20.719.819.4

Cellulose thickener 0.20.20.2

Dispersant 0.50.50.3

Wetting agent 1.51.50.5

HEUR thickener 11-

Defoaming agent 0.20.20.1

Neutralizer-0.2-

TiO₂ 15 15 12.5

CaCO3 27 27 32.3

Talc 10107.5

Acrylic adhesive 171611.1

BP - - 9.2

9800 Silicone resin emulsion

Defoaming agent 0.20.20.1

Coalescing aid 2.42.41.4

Biocide 0.10.10.1

BP - 1 -

9900 Silicone additive

Water 4.24.95.2

Total 100100100

Properties of the paint

Density 1.551.571.59

Weight percent solids 616167

Volume% solids 404147

PVC％ 67 64 63

In silicone lacquers, silicone resins are used as co-binders, for example in proportions of more than about 40% relative to the binderThe preparation is used. These resins help control water absorption and air permeability. Can be added intoAdditives such as BP 9900 increase water absorption and improve beading effect.

The use of hydrophobically modified associative thickeners can significantly enhance the rheology of aqueous latex paints. Schaller and Sperry discuss the classification of rheology control and associative thickeners in the Handbook of Coatings Additives (Vol.2, L.J.Calbo, Ed., Marcel Dekker, Inc., 1992, p.105-. When associative thickeners are used in latex paint formulations, formulation sensitivity is often a problem. This sensitivity is due to the interaction between the associative thickener and other formulation additives such as salts, surfactants, latex particles, pigment particles, and coalescing aids.

Hydrophobically modified ethoxyurethane thickeners (HEURs) contain so-called telechelic molecules (hydrophobic groups attached to the polymer end groups). At the right combination of molecular weight and half-diluted concentration, the HEUR thickener has a single stress relaxation time and exhibits shear thickening at low shear rates. At high shear rates they exhibit shear thinning and at higher concentrations exhibit pseudoplastic behavior.

E. Microorganisms

The antimicrobial agent contained in the coating composition of the present invention is effective in inhibiting the growth and/or replication of microorganisms in the coating composition and the resulting coating after application of the coating composition. In general, the antimicrobial agents of the present invention are effective in inhibiting the growth and/or replication of mold and mildew. Specifically, antimicrobial agents are effective against, for example, penicillium (Penicillium), Aspergillus (Aspergillus), Pseudomonas (Pseudomonas), spore-forming bacteria (spore-forming bacteria), Enterobacter (Enterobacter), Alcaligenes (Alcaligenes sp), Citrobacter (Citrobacter sp), Klebsiella (Klebsiella sp.), Pseudoprovidencia (Proteus-Providencia sp.), Serratia (Serrata sp.), Escherichia (Escherichia sp.), Gram-positive bacteria (Gram-positive bacteria) such as Staphylococcus (Staphyloccocus), and Streptococcus (Streptococcus); yeasts and fungi, such as Candida albicans (Candida albicans), Aureobasidium pullulans (Aurobusta pullulans), Cladosporium cladosporides (Cladosporium cladosporides), Trichoderma viride (Trichoderma viride), Alternaria alternata (Alternaria alternata. Algae), such as Chlorella pyrenoidosa (Chlorella pyrenoidosa), Ulothrix xanthate, Anabaena aquatica (Anabaena floras-aquae), Candida utilis (Nostococcus), Oscilaria profilea, etc.

F. Method of producing a composite material

The method of inhibiting microbial growth and/or replication in a coating composition of the present invention uses the antimicrobial agent described above in part a for treating a coating composition comprising the coating components described above in parts B-D and is effective to inhibit microbial growth and/or replication described above in part E. These methods are particularly suitable for coating compositions selected from the group consisting of: paints, stains, lacquers, varnishes and combinations thereof.

Definition of

An "antimicrobial agent" is an agent that inhibits the growth, replication, or both growth and replication of a microorganism. In this definition, "inhibit" is taken in its broadest sense and includes inhibiting microbial growth and/or replication, in whole or in part, including minimizing or preventing growth, replication, and/or growth and replication.

"HMTBA" means 2-hydroxy-4- (methylthio) butanoic acid.

The terms "hydrocarbon" and "hydrocarbyl" as used herein refer to organic compounds or radicals composed solely of the elements carbon and hydrogen. These moieties include alkyl, alkenyl, alkynyl and aryl moieties. These moieties also include alkyl, alkenyl, alkynyl and aryl moieties substituted with other aliphatic or cycloalkyl groups, such as alkaryl, alkenaryl and alkynylaryl groups. Unless otherwise indicated, these moieties preferably comprise 1 to 20 carbon atoms.

As used herein, a "substituted hydrocarbyl group" is a hydrocarbyl moiety substituted with at least one atom other than carbon, including moieties in which carbon chain atoms are replaced with heteroatoms such as nitrogen, oxygen, silicon, phosphorus, boron, sulfur or halogen atoms. These substituents include halogen, carbocycle, aryl, heterocycle, alkoxy, alkenyloxy, alkynyloxy, aryloxy, hydroxy, protected hydroxy, keto, acyl, acyloxy, nitro, amino, amido, nitro, cyano, mercapto (thiol), ketal, acetal, ester and ether groups.

From the detailed description of the invention, it will be apparent that modifications and variations are possible without departing from the scope of the invention defined in the appended claims. Furthermore, it is to be understood that all examples given herein are non-limiting examples.

Examples

The following non-limiting examples are presented in order to further illustrate the present invention. It should be appreciated by those of skill in the art that the techniques disclosed in the examples which follow represent examples of embodiments of the invention since the inventors have been able to practice the invention well in light of the methods described. However, those of skill in the art should, in light of the present disclosure, appreciate that many changes can be made in the specific embodiments which are disclosed and still obtain a like or similar result without departing from the spirit and scope of the invention.

Example 1

Preservative for canned paint

The paint preservatives listed in the table below were added to the aqueous paint formulations at the concentrations listed. BIOX-ASL contained 35 wt.% 2-hydroxy-4-methylthiobutyric acid (88%), 45 wt.% formic acid, 10 wt.% phosphoric acid and 10 wt.% lactic acid; BIOX-AWD contained 40% by weight of 2-hydroxy-4-methylthiobutyric acid, 40% by weight of formic acid and 20% by weight of propionic acid; BIOX-ASDA contained 36.4% by weight of calcium bis (2-hydroxy-4-methylthiobutanoate), 41.9% by weight of fumaric acid, 20% by weight of benzoic acid, 0.9% by weight of flow assistants and 0.73% by weight of further additives; HTA and BIOBAN BP30 are commercially available; BIOX-Z is HMTBA-Zn metal chelate and BIOX-C is HMTBA-Cu metal chelate.

Antimicrobial agents	Concentration of
		BIOX-A SL	10，100，1000ppm
BIOX-AWD	10，100，1000ppm
		BIOX-ASDA	5，25ppm
BIOX-C	5，25ppm

The paints were inoculated with Pseudomonas aeruginosa ATCC 10145 and Enterobacter aerogenes ATCC 13048 at a concentration of 0.1% inoculum and samples of the paints were taken over the next 7 days to determine the number of bacterial colonies still viable in the paints. The effectiveness of the added antimicrobial agent is a numerical scale given according to the following system: (0) indicating no bacteria recovery, (1) trace contamination (1-9 colonies), (2) slight contamination (10-99 colonies), (3) moderate contamination (> 100 distinct colonies) and (4) heavy contamination (continuous offset of growth). The bacterial tolerance levels are shown in tables 1, 3 and 4.

The paint was then inoculated with 1.0% inoculum and sampled again over the next 7 days to determine the number of bacterial colonies still viable in the paint. The bacterial tolerance levels for this inoculation level are shown in tables 2, 3 and 4. These grades are plotted against days post-inoculation for various concentrations of BIOX-ASL, BIOX-AWD, BIOX-ASDA and BIOX-C, and are shown in FIGS. 1-4. As shown in FIG. 5, the Minimum Inhibitory Concentration (MIC) of each BIOX microorganism was much lower after one week compared to the commercial product.

TABLE 1 bacterial tolerance grade within week 1 after 0.1% inoculum inoculation

Sample (I)	Before inoculation	Initial inoculation	Day 1	Day 2	Day 5	Day 7
							Control	0	4	0	0	0	0
10ppm BIOX-ASL	0	4	0	0	0	0
							100ppm BIOX-ASL	0	4	0	0	0	0
1000ppm BIOX-ASL	0	4	0	0	0	0
							10ppm BIOX-AWD	0	4	0	0	0	0
100ppm BIOX-AWD	0	4	0	0	0	0
							1000ppm BIOX-AWD	0	3	0	0	0	0
5ppm BIOX-ASDA	0	4	0	0	0	0
							25ppm BIOX-ASDA	0	4	0	0	0	0
5ppm BIOX-C	0	4	0	0	0	0
							25ppm BIOX-C	0	4	0	0	0	0

TABLE 2 bacterial tolerance grade at week 2 after 1.0% inoculum inoculation

Sample (I)	Before inoculation	Initial inoculation	Day 1	Day 2	Day 5	Day 7
							Control	0	4	3	3	2	1
10ppm BIOX-ASL	0	4	2	1	1	0
							100ppm BIOX-ASL	0	4	0	0	0	0
1000ppm BIOX-ASL	0	4	0	0	0	0
							10ppm BIOX-AWD	0	4	2	0	0	0
100ppm BIOX-AWD	0	4	0	0	0	0
							1000ppm BIOX-AWD	0	4	0	0	0	0
5ppm BIOX-ASDA	0	4	3	1	1	0
							25ppm BIOX-ASDA	0	4	2	0	0	0
5ppm BIOX-C	0	4	3	1	0	0
							25ppm BIOX-C	0	4	3	0	0	0

TABLE 3 bacterial tolerance grade

TABLE 4 bacterial tolerance grade

Example 2

Dry film applications

Accelerated testing of paint microorganisms was performed using an environmental chamber maintained at a constant high humidity (85-88% relative humidity) and temperature (30-33 ℃). Spores of penicillium and aspergillus are added to the environmental chamber to accelerate the formation of fungal microorganisms. The boards were coated with the experimental paint and placed in the environmental chamber for 4-12 weeks. The relative resistance of the paint to environmental indoor mold and mildew was subjectively assessed on a scale of 1-10, with 10 indicating no growth at all. The details of this test are described in ASTM D3273-94 and ASTM D3274-95.

The paint preservatives listed in table 5 below were added to the alkyd paint formulation at a concentration of 1%. HMTBA-Zn is the above-described zinc metal chelate; HMTBA-Cu is the above copper metal chelate; HMTBA-Mn is the above-described manganese metal chelate; BIOX-S is 6-ethoxy-1, 2-dihydro-2, 2, 4-trimethylquinoline; BIOX-A was 88 wt.% HMTBA; BIOX-ASL contained 35 wt.% 2-hydroxy-4-methylthiobutyric acid (88%), 45 wt.% formic acid, 10 wt.% phosphoric acid and 10 wt.% lactic acid; BIOX-EZ/7030 contained 70 wt.% 6-ethoxy-1, 2-dihydro-2, 2, 4-trimethylquinoline and 30 wt.% HMTBA-Zn metal chelate. Troy663 is a positive control (positive control).

Table 5: 1 month alkyd paint testing in environmental chamber

Table 6: 3 month continuous alkyd paint testing in environmental chamber

Chemical code	ASTM grade
		BIOX-C	9.0±0.6
Copper Wanmu ding	9.2±0.4
		Zinc Wanmu ding	8.3±0.8
Control	6.8±0.7

When referring to the invention or elements of preferred embodiments of the invention, "a," "an," "the," and "said" mean one or more of the elements. The terms "comprising," "including," and "having" are intended to be inclusive and mean that there may be additional elements other than the listed elements.

From the foregoing it will be seen that the several objects of the invention are achieved and other advantageous results attained.

As various changes could be made in the above compositions and methods without departing from the scope of the invention, it is intended that all matter contained in the above description shall be interpreted as illustrative and not in a limiting sense.

Claims (81)

1. A coating composition comprising an antimicrobial agent comprising a hydroxy analog of methionine and a binder.

2. The coating composition of claim 1, wherein the hydroxy analog of methionine is a compound having the general formula 2:

in the formula:

R³is methyl or ethyl; and

m is an integer of 0 to 2.

3. The coating composition of claim 2, wherein R is³Is methyl and m is 2.

4. The coating composition of claim 2, wherein the concentration of the compound having formula 2 in the coating composition is from about 0.0005 wt.% to about 5 wt.%.

5. The coating composition of claim 2, further comprising an additive selected from the group consisting of: pigments, fillers, biocides, and combinations thereof.

6. The coating composition of claim 2, comprising a paint comprising the coating composition.

7. The coating composition of claim 2, wherein the binder comprises a resin and an aqueous solvent, the resin selected from the group consisting of: acrylic resins, polyvinyl acetate resins, polyurethane resins, epoxy resins, and combinations thereof.

8. The coating composition of claim 7, wherein the concentration of resin in the coating composition is from about 10 wt% to about 30 wt%.

9. The coating composition of claim 7, wherein the aqueous solvent comprises water at a concentration of about 10 wt.% to about 30 wt.% in the coating composition.

10. The coating composition of claim 2, further comprising a metal salt or metal chelate comprising a metal ion and at least one hydroxy analog of methionine.

11. The coating composition of claim 10, wherein the hydroxy analog of methionine is a source of ligand or anion and is a compound having the general formula 1:

in the formula:

R¹is methyl or ethyl;

n is an integer of 0 to 2;

R²selected from hydroxyl and amino.

12. The coating composition of claim 11, comprising a metal chelate wherein the average ratio of ligand to metal ion is 2: 1; the metal ion is selected from the group consisting of: zinc ions, copper ions, manganese ions, iron ions, chromium ions, nickel ions, silver ions, cobalt ions, sodium ions, calcium ions, and combinations thereof.

13. The coating composition of claim 12, wherein the compound of formula 1 is 2-hydroxy-4-methylthio-butyric acid; the metal ion is zinc or copper.

14. The coating composition of claim 10, comprising a metal salt wherein the average ratio of anions to metal ions is 1: 1; the metal ion is selected from the group consisting of: zinc ions, copper ions, manganese ions, iron ions, chromium ions, nickel ions, silver ions, cobalt ions, sodium ions, calcium ions, and combinations thereof.

15. The coating composition of claim 14, wherein the hydroxy analog of methionine is 2-hydroxy-4-methylthio-butanoic acid; the metal ion is silver or sodium.

16. The coating composition of claim 10, further comprising at least one additional antimicrobial agent selected from the group consisting of: organic acids, inorganic acids and auxiliary biocides.

17. The coating composition of claim 2, further comprising an additional organic acid comprising at least one carboxyl moiety, pK_aLess than about 5.5.

18. The coating composition of claim 17, wherein the organic acid is selected from the group consisting of: formic acid, acetic acid, propionic acid, butyric acid, benzoic acid, lactic acid, malic acid, tartaric acid, mandelic acid, citric acid, fumaric acid, sorbic acid, boric acid, succinic acid, adipic acid, glycolic acid, glutaric acid, and combinations thereof.

19. The coating composition of claim 17, wherein the organic acid is selected from the group consisting of: formic acid, lactic acid, benzoic acid, propionic acid, and combinations thereof.

20. The coating composition of claim 17, further comprising at least one additional antimicrobial agent selected from the group consisting of: a metal salt or metal chelate of a hydroxy analog of methionine, an inorganic acid, and a secondary biocide.

21. The coating composition of claim 2, further comprising an inorganic acid selected from the group consisting of: phosphoric acid, sulfuric acid, phosphorous acid, hydrochloric acid, hydrobromic acid, nitric acid, and combinations thereof.

22. The coating composition of claim 21, wherein the inorganic acid comprises phosphoric acid.

23. The coating composition of claim 21, further comprising at least one additional antimicrobial agent selected from the group consisting of: a metal salt or metal chelate of a hydroxy analogue of methionine, an organic acid and a secondary biocide.

24. The coating composition of claim 2, further comprising a secondary biocide selected from the group consisting of: formaldehyde-releasing agents, oxazolidines, quaternized salts of Hexamethylenetetramine (HTA), bronopol, 1, 2-dibromo-2, 4-dicyanobutane (DBDCB), and combinations thereof.

25. The coating composition of claim 1, wherein the hydroxy analog of methionine comprises a metal salt or a metal chelate.

26. The coating composition of claim 25, wherein the hydroxy analog of methionine is a source of ligand or anion and is a compound having the general formula 1:

in the formula:

R¹is methyl or ethyl;

n is an integer of 0 to 2;

R²selected from hydroxyl and amino.

27. The coating composition of claim 26, comprising a metal chelate wherein the average ratio of ligand to metal ion is 2: 1; the metal ion is selected from the group consisting of: zinc ions, copper ions, manganese ions, iron ions, chromium ions, nickel ions, silver ions, cobalt ions, sodium ions, calcium ions, and combinations thereof.

28. The coating composition of claim 27, wherein the compound of formula 1 is 2-hydroxy-4-methylthio-butyric acid; the metal ion is zinc or copper.

29. The coating composition of claim 26, comprising a metal salt, wherein the average ratio of anions to metal ions is 1: 1; the metal ion is selected from the group consisting of: zinc ions, copper ions, manganese ions, iron ions, chromium ions, nickel ions, silver ions, cobalt ions, sodium ions, calcium ions, and combinations thereof.

30. The coating composition of claim 29, wherein the hydroxy analog of methionine is 2-hydroxy-4-methylthio-butanoic acid; the metal ion is silver or sodium.

31. The coating composition of claim 26, wherein the concentration of the compound of formula 1 in the coating composition is from about 0.0005 wt.% to about 5 wt.%.

32. The coating composition of claim 25, further comprising an additive selected from the group consisting of: pigments, fillers, biocides, and combinations thereof.

33. The coating composition of claim 25, comprising a paint comprising the coating composition.

34. The coating composition of claim 25, wherein the binder comprises a resin and an aqueous solvent, the resin selected from the group consisting of: acrylic resins, polyvinyl acetate resins, polyurethane resins, epoxy resins, and combinations thereof.

35. The coating composition of claim 34, wherein the concentration of resin in the coating composition is from about 10 wt% to about 30 wt%.

36. The coating composition of claim 34, wherein the aqueous solvent comprises water at a concentration of about 10 wt.% to about 30 wt.% in the coating composition.

37. The coating composition of claim 25, further comprising a hydroxy analog of methionine, which is a compound having the general formula 2:

in the formula:

R³is methyl or ethyl; and

m is an integer of 0 to 2.

38. The coating composition of claim 25, further comprising at least one additional antimicrobial agent selected from the group consisting of: organic acids, inorganic acids and auxiliary biocides.

39. The coating composition of claim 25, further comprising an additional organic acid comprising at least one carboxyl moiety, pK_aLess than about 5.5.

40. The coating composition of claim 39, wherein the organic acid is selected from the group consisting of: formic acid, acetic acid, propionic acid, butyric acid, benzoic acid, lactic acid, malic acid, tartaric acid, mandelic acid, citric acid, fumaric acid, sorbic acid, boric acid, succinic acid, adipic acid, glycolic acid, glutaric acid, and combinations thereof.

41. The coating composition of claim 39, wherein the organic acid is selected from the group consisting of: formic acid, lactic acid, benzoic acid, propionic acid, and combinations thereof.

42. The coating composition of claim 39, further comprising at least one additional antimicrobial agent selected from the group consisting of: organic acids, inorganic acids and auxiliary biocides.

43. The coating composition of claim 25, further comprising an inorganic acid selected from the group consisting of: phosphoric acid, sulfuric acid, phosphorous acid, hydrochloric acid, hydrobromic acid, nitric acid, and combinations thereof.

44. The coating composition of claim 43, wherein the inorganic acid comprises phosphoric acid.

45. The coating composition of claim 44, further comprising at least one additional antimicrobial agent selected from the group consisting of: organic acids, inorganic acids and auxiliary biocides.

46. The coating composition of claim 25, further comprising a secondary biocide selected from the group consisting of: formaldehyde-releasing agents, oxazolidines, quaternized salts of Hexamethylenetetramine (HTA), bronopol, 1, 2-dibromo-2, 4-dicyanobutane (DBDCB), and combinations thereof.

47. A method of inhibiting the growth and/or replication of microorganisms in a coating composition, the method comprising adding an antimicrobial composition to the coating composition, the antimicrobial composition comprising a hydroxy analog of methionine and a binder.

48. The method of claim 47, wherein the coating composition comprises a paint that is a water-borne paint or an alkyd-based paint.

49. The method of claim 47, wherein the concentration of the hydroxy analog of methionine in the antimicrobial composition is from about 0.0005% to about 5% by weight.

50. The method of claim 47, wherein the antimicrobial composition further comprises an additive selected from the group consisting of: pigments, fillers, biocides, and combinations thereof.

51. The method of claim 47, wherein the binder comprises a resin and an aqueous solvent, the resin selected from the group consisting of: acrylic resins, polyvinyl acetate resins, polyurethane resins, epoxy resins, and combinations thereof.

52. The method of claim 51, wherein the concentration of resin in the antimicrobial composition is from about 10% to about 30% by weight.

53. The method of claim 51, wherein the aqueous solvent comprises water at a concentration of about 10% to about 30% by weight of the antimicrobial composition.

54. The method of claim 47, wherein the hydroxy analog of methionine is a compound having the general formula 2:

in the formula:

R³is methyl or ethyl; and

m is an integer of 0 to 2.

55. The method of claim 54, wherein R is³Is methyl and m is 2.

56. The method of claim 54, further comprising at least one additional antimicrobial agent selected from the group consisting of: metal chelates or metal salts of hydroxy analogs of methionine, organic acids, inorganic acids, and secondary biocides.

57. The method of claim 54, wherein the hydroxy analog of methionine comprises a metal salt or a metal chelate.

58. The method of claim 57, wherein the hydroxy analog of methionine is a source of ligand or anion and is a compound having the general formula 1:

in the formula:

R¹is methyl or ethyl;

n is an integer of 0 to 2;

R²selected from hydroxyl and amino.

59. The method of claim 58, comprising a metal chelate wherein the average ratio of ligand to metal ion is 2: 1; the metal ion is selected from the group consisting of: zinc ions, copper ions, manganese ions, iron ions, chromium ions, nickel ions, silver ions, cobalt ions, sodium ions, calcium ions, and combinations thereof.

60. The method of claim 58, wherein the compound of formula 1 is 2-hydroxy-4-methylsulfanyl-butyric acid; the metal ion is zinc or copper.

61. The method of claim 58, comprising a metal salt wherein the average ratio of anions to metal ions is 1: 1; the metal ion is selected from the group consisting of: zinc ions, copper ions, manganese ions, iron ions, chromium ions, nickel ions, silver ions, cobalt ions, sodium ions, calcium ions, and combinations thereof.

62. The method of claim 61, wherein the hydroxy analog of methionine is 2-hydroxy-4-methylsulfanyl-butyric acid; the metal ion is silver or sodium.

63. The method of claim 57, further comprising at least one additional antimicrobial agent selected from the group consisting of: metal chelates or metal salts of hydroxy analogs of methionine, organic acids, inorganic acids, and secondary biocides.

64. The method of claim 47, wherein said antimicrobial composition further comprises at least one additional antimicrobial agent selected from the group consisting of: metal chelates or metal salts of hydroxy analogs of methionine, organic acids, inorganic acids, and secondary biocides.

65. The method of claim 64, wherein said additional antimicrobial agent is an organic acid comprising at least one carboxyl moiety and having a pKa of less than about 5.5, said organic acid selected from the group consisting of: formic acid, acetic acid, propionic acid, butyric acid, benzoic acid, lactic acid, malic acid, tartaric acid, mandelic acid, citric acid, fumaric acid, sorbic acid, boric acid, succinic acid, adipic acid, glycolic acid, glutaric acid, and combinations thereof.

66. The method of claim 64, wherein the additional antimicrobial agent is an inorganic acid selected from the group consisting of: phosphoric acid, sulfuric acid, phosphorous acid, hydrochloric acid, hydrobromic acid, nitric acid, and combinations thereof.

67. The method of claim 64, wherein the additional antimicrobial agent is a secondary biocide selected from the group consisting of: formaldehyde-releasing agents, oxazolidines, quaternized salts of Hexamethylenetetramine (HTA), bronopol, 1, 2-dibromo-2, 4-dicyanobutane (DBDCB), and combinations thereof.

68. A coating composition comprising an antimicrobial agent and a binder, the antimicrobial agent comprising a metal chelate comprising zinc ions or copper ions and at least one hydroxy analog of methionine, the hydroxy analog of methionine being a source of ligands, the hydroxy analog of methionine comprising 2-hydroxy-4-methylthio-butanoic acid.

69. The coating composition of claim 69, wherein the concentration of metal chelate in the coating composition is about 0.0005 wt.% to about 5 wt.%.

70. The coating composition of claim 68, further comprising an additive selected from the group consisting of: pigments, fillers, biocides, and combinations thereof.

71. The coating composition of claim 68, comprising a paint comprising said coating composition.

72. The coating composition of claim 68, wherein the binder comprises a resin and an aqueous solvent, the resin selected from the group consisting of: acrylic resins, polyvinyl acetate resins, polyurethane resins, epoxy resins, and combinations thereof.

73. The coating composition of claim 72, wherein the concentration of resin in the coating composition is from about 10 wt% to about 30 wt%.

74. The coating composition of claim 72, wherein the aqueous solvent comprises water at a concentration of about 10 wt.% to about 30 wt.% in the coating composition.

75. The coating composition of claim 68, wherein said antimicrobial composition further comprises at least one additional antimicrobial agent selected from the group consisting of: metal salts, anions, hydroxy analogs of methionine, organic acids, inorganic acids, and secondary biocides.

76. The coating composition of claim 75, wherein said additional antimicrobial agent is an organic acid comprising at least one carboxyl moiety and having a pKa of less than about 5.5, said organic acid selected from the group consisting of: formic acid, acetic acid, propionic acid, butyric acid, benzoic acid, lactic acid, malic acid, tartaric acid, mandelic acid, citric acid, fumaric acid, sorbic acid, boric acid, succinic acid, adipic acid, glycolic acid, glutaric acid, and combinations thereof.

77. The coating composition of claim 75, wherein said other antimicrobial agent is an inorganic acid selected from the group consisting of: phosphoric acid, sulfuric acid, phosphorous acid, hydrochloric acid, hydrobromic acid, nitric acid, and combinations thereof.

78. The coating composition of claim 75, wherein said other biocide is a secondary biocide selected from the group consisting of: formaldehyde-releasing agents, oxazolidines, quaternized salts of Hexamethylenetetramine (HTA), bronopol, 1, 2-dibromo-2, 4-dicyanobutane (DBDCB), and combinations thereof.

79. The coating composition of claim 75, wherein the metal salt is selected from the group consisting of: zinc chloride, zinc nitrate, zinc carbonate, zinc sulfate, zinc acetate, zinc formate, zinc ammonium sulfate, zinc phosphate, zinc stearate, and combinations thereof.

80. The coating composition of claim 75, wherein said anion is selected from the group consisting of: chloride, nitrate, carbonate, sulfate, acetate, formate, ammonium sulfate, phosphate, stearate, and combinations thereof.

81. The coating composition of claim 68, wherein the metal chelate has an average particle size of about 0.05 to about 8 microns.