Biocide composition comprising zinc pyrithione and a pyrrole derivative

[0001] This invention relates to a biocidal composition. More specifically, the invention relates to a biocidal composition comprising a mixture of a selected pyrithione compound and a selected pyrrole derivative that prevents or inhibits the growth of microorganisms and the method of using such a biocidal composition.

Brief Description of the Prior Art [0002] A variety of compositions and preparations are known in the art for the prevention, inhibition and management of microbial growth or plague. Similarly, there are many compositions and coatings formulated specifically for the prevention, inhibition and management of growth or plague of fouling organisms.

[0003] Fertilizing organisms present a significant problem for substrates and objects that are exposed to water. The term "fouling organism" includes both hard and soft growing organisms. Hard growing organisms include barnacles, molluscs and the like, while the soft growing organisms include algae, fungi, and organisms listed in US Patent No. 5,712, 275. Such organisms present a continuous problem for objects and substrates that are exposed to water seawater, fresh water, brackish water, sewage water, waste water, rainwater and the like.

[0004] Fertilizing organisms grow, attack or adhere to various types of substrates and objects that are exposed to any type of water. Growth or attack by growing organisms on surfaces is visually unattractive. Moreover, the increase may cause some problems with the use of substrates and objects to which the growing organisms have stuck or attacked. For example, one of the problems that often occurs is the attachment of hard organisms that grow into the ship's hull. Organisms cause the surface of the ship to become rough, thus reducing the speed of the ship.

[0005] Moreover, wood and wood products are often the victim of the growth and attack of microorganisms such as fouling organisms, termites and the like. The growth and attack of such microorganisms leads to warping, cracking and deterioration of wood and wooden products. As a result, timber and wooden products lose their value, visual attractiveness and usability.

[0006] In order to overcome this problem, biocide-containing coatings have been developed. Examples of biocides that have been found to be useful include tributyltin compounds, pyrithione compounds, oxathazine compounds, pyrrole compounds, triphenyl boronic compounds and terbuthrin.

[0007] Pyrithione compounds and selected pyrrole compounds are separately known and used as biocides or antifoulants. However, it is not known or obvious in the art to combine these two compounds. Examples of literature references regarding the prior art, disclosing the use of pyrithione compounds and selected pyrrole compounds, include the following:

[0008] US Patent No. 5 057 153 to Ruggiero relates to an improved composition of primer paints or paints that are characterized by increased biocidal efficiency. The paint contains a biocide including the pyrithione salt and copper salt. Moreover, in U.S. Patent No. 5,246,489 to Farmer Jr. and others the process of producing a biocide - copper pyrithione in-situ in a paint preparation has been disclosed. The primer paints and paints of this patent include pyrithione compounds as the only biocide present in the formulation.

[0009] U.S. Patent No. 5,098, 473 to Hani et al. it relates to primer paints and paints, more specifically to the process of providing a stable, gel-free dispersion of zinc pyrithione with copper oxide in paints (see also US Patent Nos. 5,098, 473; 5,122,397,50, 5,55, 5,930,033; 5,222; 493; 5 298 061; 5 342 437; PCT Patent Application No. WO 95/10568 and EP 0610251).

[0010] US Patent No. 4,957,658 from French et al. it concerned primers and paints, and more specifically the process and composition to ensure reduced discoloration of primer paints and paints containing pyrithione and iron (III).

[0011] U.S. Patent No. 4,399, 130 to Davidson et al. describes a method employing an effective amount of at least one pyridin-2-thione metal salt of pyrimidine N-oxide to treat or prevent porcine epidermal inflammation.

[0012] U.S. Patent No. 4,496,559 to Henderson et al. describes selected 2-selenopyridine-N-oxide derivatives for use as fungicides and bactericides. [0013] US Patent No. 4,555,856 to Trotz et al. refers to polymers containing pyrithione. The polymers described in this patent are used as biocides in paints and wood preservatives.

[0014] US Patent No. 4,610,993 to Vedas et al. describes a method of administering an effective amount of at least one selected pyridine-N-oxide disulphide compound to treat or prevent mastitis in cattle. [0015] European patent number EP 0746979 describes a method for controlling or controlling adherence of a fouling organism to an underwater surface by contacting the body with an effective amount of a 2-aopyrrolol compound.

[0016] US Patent No. 6,069,189 (corresponding to EP 0831134 A1) from Kramer et al. describes antifouling paints that contain selected pyrrole derivatives. Specific pyrrole compounds included in antifouling paints include 2-trihalogenomethyl-3-halo-4-cyanopyrrole and its derivatives. Kramer et al. they found that these compounds are particularly effective against the attack of barnacles. What's more, it's a literature reference to Kramer and others discovers that a shimmering or bright color antifouling can be produced despite the addition of these compounds.

[0017] PCT Patent Application No. WO 03/039256 describes an anti-fouling composition that contains an amount of at least 3.5 wt%. based on the total dry weight of the composition of 4-bromo-2- (4-chlorophenyl) -5- (trifluoromethyl) -1H-pyrrole-3-carbonitrile, or a salt thereof, together with another biocide. Another biocide is selected from betoxazine, tolylfluanid, dichlofluanid, or DCOIT. [0018] PCT Patent Application No. WO 2007/088172 describes combinations of 4-bromo-2- (4-chlorophenyl)) - 5- (trifluoromethyl) -1H-pyrrole-3-carbonitrile and copper or zinc compounds for protection against fouling organisms, such as aquatic organisms.

[0019] European Patent No. 0312723 describes methods and compositions for controlling molluscs including contacting molluscs with carbonitrile compounds.

[0020] European Patent No. EP 1080640 describes coating compositions having anti-fouling effects on ships, the compositions comprising copper bis (2-pyridinium thiol-1-oxide) salt.

[0021] Bellas et al. "Embryotoxicity of the antifouling biocide zinc pyrithione to sea urchin (Paracentrotus lividus) and mussel (Mytilus edulis)" describes zinc pyrithione as an antifouling compound and its effect on sea urchin and edible mussel.

[0022] WO 2005/075581 A1 describes antifouling compositions comprising a polymer with salt groups. The compositions may contain copper or zinc compounds, such as zinc pyrithione and / or "non-metallophilic" biocides, such as isothiazolones or 2- (p-chlorophenyl) -3-cyano-4-bromo-5-trifluoromethylpyrrole.

[0023] Despite advances in the field, what is still needed is a coating that contains a biocidal composition that could be effective against a broad spectrum of microorganisms, and also exhibits high stability and low toxicity. Ideally, the coating and composition would be easily and inexpensively manufactured. The present invention is intended to be a response to the problems discussed above.

BRIEF SUMMARY OF THE INVENTION [0024] One aspect of the present invention is directed to a coating composition comprising a biocidal effective amount of a biocidal composition comprising zinc pyrithione and 4-bromo-2- (4-chlorophenyl) -5- (trifluoromethyl) -1H-pyrrole-3 carbonitrile, wherein said biocidal composition is copper-free or has a low copper content, i.e. the total amount of copper is less than 3% by weight, based on the total weight of the composition.

[0025] Another aspect of the present invention is directed to a method of coating a substrate comprising applying to the substrate a coating composition that comprises a biocidal composition as described above, and drying the coating composition on a substrate.

[0026] Yet another aspect of the present invention is directed to a coated substrate comprising the coating composition of the present invention and a substrate, wherein said substrate is selected from the group consisting of wood, plastic, leather, vinyl and metal.

[0027] One of the expected advantages of the present invention includes increased protection against a broad spectrum of microorganisms. Another of the expected advantages of the present invention includes the preservation of wood and wood products. Moreover, it is expected that the present invention will be long-lasting, will have low toxicity, and will be easily and inexpensively manufactured.

DETAILED DESCRIPTION OF THE INVENTION [0028] The term "biocidal effective amount" as used in the present specification and claims refers to an amount of a biocidal composition that has a positive effect on reducing, eliminating or preventing attachment or growth of microorganisms on a substrate.

The term & quot; microorganism & quot; as used in the present specification and claims includes algae, fungi, biofilms, insects, fouling (including both hard and soft growing organisms), or any organism that can attach to, grow on or destroy materials such as wood, concrete, paper, plastic, and the like.

[0030] The term "copper-free or low-copper", as used in the present specification and claims, means that the compositions do not contain copper or contain copper in a total weight percentage of less than 3 wt%, based on the total weight of the formulation. .

[0031] The term "wood products" as used in the present description and claims includes materials that comprise or are derived from wood, including, but not limited to, fibreboard, chipboard, plywood, oriented fiberboard, wood laminated, pressed wood and the like.

[0032] As indicated above, one aspect of the present invention is a coating composition comprising a biocidal composition comprising zinc pyrithione and the above-described pyrrole compound. Each of these ingredients is discussed in more detail below.

[0033] Pyrithioneates are generally widely known and often used in many applications, including paints and personal care products. Pirytioniany are excellent biocides, and can be found in antifouling paints for marine applications. Furthermore, metal salts of pyrithione, including tin, cadmium and zirconium salts, are suitable for use in shampoo.

[0034] Pyrithione compounds are compounds with the following basic structure:

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[0035] A pyrithione compound suitable for use in the present invention is zinc pyrithione, which has excellent biocidal activity. Zinc pyrithione has a low solubility in salt water, which makes it more stable than other pyrithione salts.

[0036] Zinc pyrithione may be prepared by the methods described in U.S. Patent No. 2,809,971 to Berstein et al. Other patents disclosing similar compounds and processes for making them include U.S. Patents No. 2,786,843; 3,589.999; and 3,773,770.

[0037] Furthermore, the biocidal composition in the coating composition of the present invention comprises a pyrrole compound as shown above, namely, 4-bromo-2- (4-chlorophenyl) -5 (trifluoromethyl) -1H-pyrrole-3-carbonitrile.

[0038] The above-mentioned pyrrole may be formulated using the methods described in U.S. Patents 5,310,938 and 5,328,928.

[0039] To ensure biocidal performance, zinc pyrithione and pyrrole are present in the biocide composition in a weight ratio of 3: 2 to 2: 3.

[0040] The biocidal composition is present in the coating composition in a biocidal effective amount. Preferably, the biocidal composition is present in an amount between 1% and 15% by weight, based on the total weight of the coating composition. More preferably, the biocidal composition is present in an amount between 1% and 10% by weight, based on the total weight of the coating composition. Most preferably, the biocidal composition is present in an amount between 3% and 8% by weight, based on the total weight of the coating composition.

[0041] In addition to the biocidal composition, the coating composition may also include additives. Such additives may include, but are not limited to, organic binders; additives that facilitate processing; fixing agents, such as polyvinyl alcohol; plasticizers; UV stabilizers; dyes; colored pigments; anti-deposition agents; antifoam agents; additional insecticides such as chlorinated hydrocarbons, organic phosphates and the like; additional fungicides and bactericides, such as alcohols, aldehydes, formaldehyde releasing compounds and the like; phenols; organic acids such as propionic acid, benzoic acids and the like; inorganic acids, such as boric acid; amides; azoles; heterocyclic compounds; N-haloalkylthio compounds; and the like. Polymers, such as acrylic polymers or acrylic copolymers, which are self polishing for use in, for example, antifouling coatings for marine applications, may also be used. Preferably, these polymers are tin-free. Examples of acrylic polymers or copolymers that can be incorporated into the compositions of the invention include a copper acrylate polymer or copolymer, a zinc acrylate polymer or copolymer, a silyl acrylate polymer or copolymer, and the like. Additional polymers known in the art, associated with paints and coatings, may also be used in the composition of the invention. Additives present in the coating composition will depend on the preferences of the user or manufacturer as well as the final application of the coating composition. which are self-polishing for use in, for example, antifouling coatings for marine applications, can also be used. Preferably, these polymers are tin-free. Examples of acrylic polymers or copolymers that can be incorporated into the compositions of the invention include a copper acrylate polymer or copolymer, a zinc acrylate polymer or copolymer, a silyl acrylate polymer or copolymer, and the like. Additional polymers known in the art, associated with paints and coatings, may also be used in the composition of the invention. Additives present in the coating composition will depend on the preferences of the user or manufacturer as well as the final application of the coating composition. which are self-polishing for use in, for example, antifouling coatings for marine applications, can also be used. Preferably, these polymers are tin-free. Examples of acrylic polymers or copolymers that can be incorporated into the compositions of the invention include a copper acrylate polymer or copolymer, a zinc acrylate polymer or copolymer, a silyl acrylate polymer or copolymer, and the like. Additional polymers known in the art, associated with paints and coatings, may also be used in the composition of the invention. Additives present in the coating composition will depend on the preferences of the user or manufacturer as well as the final application of the coating composition. these polymers are tin-free. Examples of acrylic polymers or copolymers that can be incorporated into the compositions of the invention include a copper acrylate polymer or copolymer, a zinc acrylate polymer or copolymer, a silyl acrylate polymer or copolymer, and the like. Additional polymers known in the art, associated with paints and coatings, may also be used in the composition of the invention. Additives present in the coating composition will depend on the preferences of the user or manufacturer as well as the final application of the coating composition. these polymers are tin-free. Examples of acrylic polymers or copolymers that can be incorporated into the compositions of the invention include a copper acrylate polymer or copolymer, a zinc acrylate polymer or copolymer, a silyl acrylate polymer or copolymer, and the like. Additional polymers known in the art, associated with paints and coatings, may also be used in the composition of the invention. Additives present in the coating composition will depend on the preferences of the user or manufacturer as well as the final application of the coating composition. Additional polymers known in the art, associated with paints and coatings, may also be used in the composition of the invention. Additives present in the coating composition will depend on the preferences of the user or manufacturer as well as the final application of the coating composition. Additional polymers known in the art, associated with paints and coatings, may also be used in the composition of the invention. Additives present in the coating composition will depend on the preferences of the user or manufacturer as well as the final application of the coating composition.

[0042] The coating composition is produced by combining the biocide composition and additives with a primer paint material, such as a primer paint for marine applications. Methods for forming such coating compositions are well known in the art. Examples of such methods include, but are not limited to, combining a biocide composition and additives in a mixing mechanism. The mixing mechanism would evenly disperse the biocidal composition among the additives. Additional methods for forming a coating composition can be used as is known to those skilled in the art. Furthermore, any primer paint material that is suitable for marine applications, including water or solvent based formulations, may be used in the coating composition of the invention. Such paints for marine applications are known in the art, as shown, for example, in U.S. Patent Nos. 6,710,117; 4,981,846; 4,426,464; 4,407,997; and 4 021 392.

[0043] The coating composition can take many forms. These forms include, but are not limited to, paints (in particular anti-fouling paints), varnish, lacquer, liquid, wood sealant, or any other form that can be used to cover the material. [0044] Another aspect of the invention includes a method comprising applying a coating composition as described above to a material to be protected. The coating composition may be applied in a variety of ways that include, but are not limited to, brushing, spraying, sponge application, spraying, or dipping, sinking, soaking the material therein. Preferably, the coating composition is applied uniformly to the material. When the coating composition is applied to the material, it should be allowed to dry to ensure proper adhesion to the material. Drying can be achieved by exposure to air or by using a mechanism that allows faster drying, such as heating lamps or a hot air generator.

[0045] The material that may be protected by the coating composition includes wood, leather, vinyl, plastic, concrete, gypsum, paper and any other material that may be exposed to microorganisms or water containing such microorganisms. Ideally, the material should be sufficiently porous to allow the coating composition to penetrate and adhere to the material. [0046] Another aspect of the invention includes a coated substrate. The coated substrate includes a material such as those described above that has been coated with a coating composition. Substrates that can best benefit from the application of the coating composition include a normal substrate for marine applications, such as ship hulls, docks, piers, buoys, fishing devices, fishing nets, lobster traps, bridges and piling.

[0047] The substrate is expected to exhibit biocidal properties when coated with the coating composition. The biocidal properties will prevent, inhibit or act on the attachment or growth of microorganisms on or in the substrate. Prevention or management of such growth will allow release of the microbial substrate. In addition to being visually appealing, the substrate will be free of microbes, allowing it to be used in the way its use was planned.

[0048] Furthermore, it is expected that the wood or wooden products that are coated with the coating composition will exhibit microbial resistance. The application of the coating composition to wood and wood products is expected to prevent the visual attractiveness and usefulness of wood and wood products from being destroyed by microorganisms such as fungi, algae, termites and the like. Commercial and residential products and structures that could benefit from such applications include staircases, floors, cabinets, piers, piers, shingles, piling, fences, furniture, mailboxes and the like.

EXAMPLES [0049] The following Examples further illustrate the present invention. All parts and percentages are by weight unless clearly stated otherwise. All temperatures are in degrees Celsius unless clearly stated otherwise.

Efficacy Test of paints [0050] A series of nine paint formulations containing 4-bromo-2- (4-chlorophenyl) -5- (trifluoromethyl) 1H-pyrrole-3-carbonitrile (referred to in this table as Pirol) and zinc pyrithione (ZPT) have been investigated by Duke University off the Beaufort, North Carolina coast, in 2004 for their antifouling effectiveness against barnacles and other fouling organisms. The formulations were prepared in the laboratory by adding different amounts of biocides to the resin-based formulation (vinyl resin / wood resin with a filler - Zn oxide). The formulations include 4-bromo-2- (4-chlorophenyl) -5- (trifluoromethyl) -1H-pyrrole-3-carbonitrile alone or in combination with ZPT. The solvent-based zinc oxide coating was used as a control. Unprimed fiberglass rods (8 mm in diameter x 11 cm in length) were coated by dipping into each specimen (5 rods / specimen) and suspended on a research stand in the ocean (one meter below the surface). The rods were assessed every month for the number of barnacles and bryozoans. The most promising results were obtained by formulations in which 4-bromo-2- (4-chlorophenyl) -5- (trifluoromethyl) -1H-pyrrole-3-carbonitrile was mixed with ZPT (See Table 1 below).

[0051] Bryblers are highly complex colonial animals composed of individual "zooids", all of them connected by living tissue. Zooids are protected inside a cup or box shaped exoskeleton with calcified chitin tissue. The degree of calcification determines how rigid or flexible the whole structure is. Brygoths are eaten by many grazing animals, such as sea urchins and various molluscs.

[0052] Studies confirm that 4-bromo-2- (4-chlorophenyl) -5- (trifluoromethyl) -1H-pyrrole-3-carbonitrile is an effective antifouling agent for heavily fouling organisms, such as barnacles, which is compatible with ZPT , and that works better with ZPT as a co-biocide than itself.

Table 1

<td colspan="2">DATE</td><td colspan="2">Average from 2 months 7/16/04</td><td colspan="2">Average from 3 months 8/13/04</td><td colspan="2">Average from 4 months 9/15/04</td><td colspan="2">Average from 5 months on 10/13/04</td>

<td>CODE</td><td>RHODIUM #</td><td>bryozoans</td><td># FAMILY</td><td></td><td># FAMILY</td><td>bryozoans</td><td># barnacles</td><td>bryozoans</td><td># barnacles</td>

<td>CONTROL - Lack biocide</td><td>1</td><td>7.8</td><td>18.2</td><td>0</td><td>14</td><td>4</td><td>14.5</td><td>M</td><td>M</td>

<td>8% Pirol biocide</td><td>2</td><td>0.4</td><td>1</td><td>0</td><td>4</td><td>2.2</td><td>8.6</td><td>M</td><td>1</td>

<td>6% Pirol Biocyd</td><td>3</td><td>0.4</td><td>1.4</td><td>0</td><td>7</td><td>0.6</td><td>5.6</td><td>0.2</td><td>0.8</td>

<td>4% Biocide</td><td>4</td><td>0</td><td>0.8</td><td>0</td><td>5.6</td><td>0.4</td><td>4</td><td>0.4</td><td>1.6</td>

<td>5% Pirol 4% ZPT</td><td>5</td><td>0</td><td>0.4</td><td>0</td><td>1</td><td>0</td><td>3.4</td><td>0</td><td>0.8</td>

<td>5% Pirol 2% ZPT</td><td>6</td><td>0</td><td>0.6</td><td>0</td><td>1.8</td><td>0</td><td>1.4</td><td>0</td><td>0.4</td>

<td>2% Pirol</td><td>7</td><td>0</td><td>1</td><td>0</td><td>16</td><td>0</td><td>3.2</td><td>0.2</td><td>1.2</td>

<td>2% Pirol 4% ZPT</td><td>8</td><td>0</td><td>0.2</td><td>0</td><td>12.2</td><td>0.4</td><td>4.4</td><td>0</td><td>2</td>

<td>2% Pirol 2% ZPT</td><td>9</td><td>0</td><td>0.8</td><td>0</td><td>9.4</td><td>0</td><td>3.8</td><td>0</td><td>1.2</td>

<td colspan="10">Notes: "M" refers to the mature growing population. The growth cycle of certain marine organisms may cause a difference in the average number of readings per month in the table above. Experiments 1-4 and 7 are comparative; experiments 5 and 9 are according to the invention; Experiments 6 and 8 are not according to the invention.</td>

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PL-PAT-2012-1029

EP 1 998 619 B1